I agree with Minn about the RX being "swamped" which simply means it is receiving too strong of a signal.

As for the loose crystal theory? Well I must be the odd one out here as I hear so many stories about this but have never seen this actually happen in close to 30 years of flying. NOT saying it can't happen but unlikely. I usually have to fight to get one to come out when I want it to. If your RX is/was wrapped with foam you should be fine. Most trees landings aren't that stressful on Receivers. Not too good on wings though .