Whiplash patients can certainly tests a physio's ability in many ways . Not the least of which is to be able to construct a usefull treatment regimen that minimises post Rx irritation and sets a course for stability, movement and comfort. Post Rx irritation is common with these people. In some cases even pulsed US can irritate. As long as you are both prepared to comunicate , to modify , to establish a good relationship based on mutual trust and respect you will work out the way to proceed together.
Hands are great things. Use them with care and restraint here though.