The discussion so far has been most helpful.
I'm considering putting this into our syllabus to help those just starting in flight test to avoid problems we've all faced.
As far as suggesting fixes goes, that was one of the things I was taught at ETPS many years ago - don't tell them how to fix the problem exactly - tell them what you want as an outcome and see what they come up with.
Teamwork and a clearly defined view of where the project is going is essential.