At what point was the extra $100 known to the BL?
Was it discussed at the time of the exchange, or did the manager just hand him a wad of cash?
Was it acknowledged by the BL (to the manager) at any time?
(not that it really matters at this point, but it would clarify the manager's
intent.)
If it was the manager's intent to tip - they have an internal issue.
If it was an honest mistake/wasn't specifically mentioned, it won't help your reputation to keep the $.
Tacky move by the owner either way, but it's your issue to resolve now
("it never gets weird enough for me".
Should we offer to discount another gig?
Whatever the intent - it was THEIR error. - wondering why the owner wouldn't just offer to re-book you and consider it an advance.
Sort of tells you where you stand in this relationship.
Since you had a contract, and this is causing a dispute - a $100 -
split- isn't going to change anyone's life...
Edit: Here's a scenario to consider;
Crazy owner fires manager. Manager ends up working at your favorite / best playing club....