If they just smashed a window and didnt cause major damage, tell the (car) insurance company a stone was flicked up by a passing vehicle and smashed it…
That way it just counts as a windscreen claim and not theft so will have much less (if any) effect on future policy prices, if you report as theft they will probably give you naff all for you bike and then charge you for the privilege in future.
But if he then claims on house insurance for the bike theft that would likely be classed as insurance fraud, and given the circumstances (claiming on house insurance for theft from a car) is quite likely the two companies would talk to each other to ensure there isn’t another claim for the same incident