Depends what the issues are as to whether there is any come back for people after
Police will deal with any significant RTA issues, such as failure to report, doing a runner etc. Insurance companies will tend to piggy back of these sorts of things if resolved quickly
The ins cos are trying to deal with the situation and close it asap. They don't want stuff hanging on and open for long periods, the workload, but also they cannot finalise their liabilities.
Its not really fraud, its attempted fraud in effect, plus with enough options of excuses etc thats why very few people will be progressed, again see above, they want this stuff closed off.
Oddly they will however go after people far more aggressively afterwards if it does become fraud as opposed to attempted, so if someone does lie, get away with something then later its found out.
Its why they seem to go after policy holders who mis declare mods yet seemingly not after rejected claims for whiplash etc. One is proven fraud, the other is attempted.