At page 1837, having disposed of an Article 6 point, Lord Woolf MR said,

In a substantial case such as this, the correct approach is to regard the instruction of an expert jointly by the parties as the first step in obtaining expert evidence on a particular issue. It is to be hoped that in the majority of cases it will not only be the first step but the last step. If, having obtained a joint expert’s report, a party, for reasons which are not fanciful, wishes to obtain further information before making a decision as to whether or not there is a particular part (or indeed the whole) of the expert’s report which he or she may wish to challenge, then they should, subject to the discretion of the court, be permitted to obtain that evidence.

In the majority of cases, the sensible approach will not be to ask the court straight away to allow the dissatisfied party to call a second expert. In many cases it would be wrong to make a decision until one is in a position to consider the situation in the round. You cannot make generalisations, but in a case where there is a modest sum involved a court may take a more rigorous approach. It may be said in a case where there is a modest amount involved that it would be disproportionate to obtain a second report in any circumstances. At most what should be allowed is merely to put a question to the expert who has already prepared a report.

…In a case where there is a substantial sum involved, one starts…from the position that, wherever possible, a joint report is obtained. If there is disagreement on that report, then there would be an issue as to whether to ask questions or whether to get your own expert’s report.

If questions do not resolve the matter and a party, or both parties, obtain their own expert’s reports, then that will result in a decision having to be reached as to what evidence should be called.

That decision should not be taken until there has been a meeting between the experts involved. It may be that agreement could then be reached; it may be that agreement is reached as a result of asking the appropriate questions.

It is only as a last resort that you accept that it is necessary for oral evidence to be given by the experts before the court. The cross-examination of expert witnesses at the hearing, even in a substantial case, can be very expensive.

Judgment edited for ease of reading.