Warren its like all lighting strikes and near misses and there is no proven solution as of yet. Sometimes in an anchorage the only boat struck was the one that was grounded yet the opposite occurs in other strikes.
I’ve personally been in a few heavy lightening storms and have been lucky to have lost just my radio and lighting the instant the lightening flashed.
There’s a lot of stories out there where through hulls have been blown out and who knows about some boats that were lost at sea...Maybe the Propane tanks were struck.. Ouch!