When people are called into a case as an EXPERT witness, their role is to advise the court......not to side with either party! This is a fact often lost on participants at court when called in that capacity and it is one of the main reasons that CASA often loses cases when they call their own to provide expert testimony. Also often lost is the term EXPERT; just being employed in a particular industry DOES NOT qualify one as an expert....in the medical fraternity, there is a very specific definition that is often lost on other industries!
As for the question about conducting a steep turn in a helicopter at 21" MAP......it is very likely and indeed possible due to the application of 'other' forces such as aft cyclic.
IMHO, whoever was flying that machine deserved to have his licence suspended although it is not apparent that that person was JQ unless someone fingered him for the job! Those types of manoeuvres, low level and over water, are unacceptable on a fare paying passenger (read Charter) flight!