That is an awfully tricky situation. And it really stinks that he is unwilling to accept what you say as the truth!

Has he always been a jerk, or is this attack highly unusual? Just curious if chances are high that he's made similar assumptions towards previous staff that he employed. If so, that would make the list of possible thieves larger.
If this behavior is entirely new and highly unusual...hopefully, he'll calm down soon and see the wine bottle opener right before his eyes in some strange spot.
Either way, I hope that this mess is figured out soon and you aren't blamed & assumed guilty for stealing. You deserve to be treated better than this! * I hope that things settle down for you soon *