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Freshfields Risk & Compliance

| 5 minutes read

Expert evidence in the virtual environment – lessons learned in 2020

The COVID-19 pandemic brought about an unprecedented overnight change to the hearing process, with most hearings being held either semi or fully remote.

One year on, a joint Freshfields/HKA panel comprising of Jane Jenkins, Tom Hutchison and Stephanie Mbonu of Freshfields, and Derek Nelson, Partner at HKA and Chairman of the Academy of Experts, considered: 

  • some of the key challenges faced over the past year; 
  • how these challenges have been overcome, including lessons learned; and 
  • future trends in a post-pandemic era. 

This blog post summarises the key takeaways from the discussion, which can be heard in full here.

Challenges in preparing for hearings virtually

One of the biggest challenges in the switch to virtual working is managing time effectively. Before the pandemic, lawyers and experts could come together in physical meeting rooms and spend hours preparing to give evidence. This time was used to develop and rehearse presentations and run mock cross-examination sessions. In the virtual world, two to three hours has proved to be the maximum length of time a video call can be productive. Therefore, to ensure preparation sessions are effective, they are split up into short chunks, sometimes over several days. This is even more challenging where different time zones are involved. For example, where an expert is in Australia and counsel is in the UK, there can be a relatively narrow window to hold a meeting with all the parties within reasonably sociable hours. Flexibility is therefore key and finding a rhythm between counsel and experts is important for effective preparation.

The discipline of effective preparation before shorter meetings using a clear focussed goal and agenda, with a period of reflection between each session, has delivered valuable efficiencies. While virtual preparation brings its own challenges there are also positive lessons to be carried forward when face-to-face preparation is once again possible.

Effective preparation for the hearing itself

The key to preparing for a virtual or hybrid hearing is to simulate how you would prepare for an in-person hearing as closely as possible. An important step, which should be done as early as possible, is to prepare an electronic bundle. This is the best way to ensure that you and the expert are working from the same set of documents during virtual preparation. This will also help build familiarity between the expert and the documents ahead of the hearing.

Engaging a third-party document services provider to host the online hearing bundle, for example Opus2 or Epiq. Parties can then mark up, highlight or tag their own copy of the documents, much like they would with a physical copy, and the bundle can be easily adjusted as preparation develops. For smaller hearings, an offline PDF bundle may suffice. Parties will still be able to tag and mark up PDF copies of the documents with the appropriate software.

Effective set-up is a vitally important step in running a successful virtual hearing. It is advisable that experts have at least two screens in front of them, one for the videoconference and one for the display of evidence (or the hearing bundle). This may require a small investment in technology. Alternatively, the expert could attend from a hearing centre or an office, which already has the technology capabilities in place as opposed to from home. This has the additional benefits of a stable internet connection, minimised risk of interruptions, and helping the expert 'get in the zone' to give evidence.

Engaging a hearing centre to facilitate the virtual hearing platform is another important investment. A hearing manager will be assigned to set up the platform and test the technology with the parties. They will also monitor the virtual waiting room which is an important security measure to ensure only authorised persons gain access to the hearing. It is crucial the system is tested, ideally twice, ahead of the hearing to avoid unnecessary delays. The first test should be about two weeks before the hearing and the second, the day before the hearing day begins.

The key takeaway here is to become familiar with the technology, be creative in how it can be used and then trust in it. For example, WhatsApp can effectively replace the traditional passing of post-it notes at a physical hearing.

Can 'hot-tubbing' be effective in the virtual environment?

Concurrent cross-examination, commonly referred to as 'hot-tubbing', is a style of cross-examination in which both sides' experts are questioned at the same time. The problem with this in the virtual environment is that when a person attempts to speak at the same time as someone else it has the effect of muting the other person. This is unhelpful for those speaking and the tribunal (and transcriber) listening. This is less likely to happen in traditional cross-examination.

If hot-tubbing is ordered by the tribunal, it is crucial that the parties agree on a protocol in advance. The agreed protocol should, at a minimum, include a provision setting out how experts should seek the attention of the tribunal before moving on to another subject. This could be through asking the tribunal to ensure each expert has the chance to respond or expand on a point once the other expert has finished speaking. Or use of the 'raised hand' function which allows the expert to mark his or her wish to speak without talking over or muting those speaking.

Although, anecdotally, virtual hearings appear to lend themselves more towards traditional cross-examination, with an agreed protocol in place, and appropriate leadership from the tribunal, there is no real reason why virtual hot-tubbing cannot be effective. 

Future trends

It is unlikely that in-person hearings will be fully replaced. However, virtual or hybrid hearings may become the default position for smaller, less complex cases as the efficiency gains far outweigh any due process concerns. (For more on this, see Freshfields’ International arbitration: top trends of 2021 publication.)

For larger, more complex disputes, there is likely to be an increase in hybrid hearings, which will have a combination of parties being either physically or virtually present. While this may allow for greater flexibility in scheduling, choice of experts and choice of arbitrators, it may also give rise to due process challenges based on procedural unfairness and/or inequality of representation. This increases the possibility of an award challenge. It is too early to tell whether there is likely be an increase in challenges based on a tribunal’s decision to order a remote hearing, where a resisting party has reserved its rights to do so. However, many arbitral institutions have updated their rules to allow for virtual hearings, which should minimise such challenges.

In any virtual or hybrid hearing, the guiding principle must be fairness of the proceedings and the importance of creating a level playing field. For example, if one expert cannot attend in person, consider whether both experts should give evidence virtually. Best practice would be for any issues regarding procedural fairness to be determined at the outset rather than a party proceeding under reservation of its position.


Virtual hearings will no doubt play a significant role in shaping arbitration hearings in the years to come. For experts and counsel alike this will continue to be a learning curve, but there are excellent resources available to help guide the parties, such as the Academy of Experts’ helpful guidance on the giving of remote evidence.


construction and engineering, arbitration