The biggest issue here AFAIAC is that litigeous actions can prevent or hamper the embedding of learning.
The whole purpose of the AAIB and other such organisations is to determine, learn, improve and embed, the latter could be system improvements, SOP inprovements etc etc.
The system works because we are effectively 'policed by consent'.
When the lawyers, who probably see this as big buck win territory, start getting involved, the whole process is threatened. We could lose the ability to rationally assess and replace that with blame, then the continual improvements that increase air safety will be jepordised.
Furthermore, the MO of the investigators is to establish facts; the MO of lawyers is to INTERPRETE facts. There is, IMO, a huge difference in those agendas, and with respect, unless said Lawyer/Judge actually understand fully how to fly/control an airplane, the facts could very well be mis-interpreted (or spun) as mentioned by another poster above.
(For the record, I could never contenance WILLFULLY ignoring checklists or SOP's. )