Try to nudge the fish a little if its still in there(possible) and be sure his gills can move freely.
If you are really desperate, you could cut the log open with pliers or something while keeping it submerged in water(not the main tank)
Be sure no rusty metal is able ot get into your tank or it will be a disaster!
If you get him out and he was indded stuck, then you will knwo now ot remove hte log from the tank to prevent this from happening again.
