From my 20 years of DJing in public, I can assure you that it's impossible to assume bar managers are decent or understanding regardless of their experience.
I've had more run ins with managers than I care to remember. I walked away from one of my first residencies after the alcoholic manager told me to "bang it out" and "play like a Saturday" on a Tuesday night because it was a little busier than usual. I was hesitant but did what he asked, he ever kept pushing the volume up on the main control behind the bar. Inevitably the place emptied and he genuinely had the cheek to come over and remark, and I quote, "well you fucked that up" at which point I stopped the music and packed up my records (yes, this was back in the vinyl days and before venues had Spotify for their background music) and took every CD in the booth the ensure they had literally no music for the rest of the night. The shit bag even locked himself in the office and asked the doorman to not let me back in, as I had said I was still getting paid regardless. The doorman was a friend of mine and wasn't willing to get involved. I took the money from the till behind the bar, since he refused to come out of the office, and advised the remaining customers there would be no more music and to try one of the neighbouring bars.
About a month later he was sacked for drinking on the job, bullying his bar staff and stealing money. As for me...well I had the owner of the company ask for me to go back, and negotiated a payrise.
I eventually left on bad terms a couple of years later, over pay issues (they were trying to dock my wages when it was quiet). I had the manager at the time assist me in stealing the Technics turntables that were, at that point, collecting dust as CDJs had come in by then.
Believe it or not, I briefly went back to work there for a third time but was snapped up by a competitor and the bar I'd left went bust shortly after (not claiming that was down to me, they were clearly in financial shit for a while hence them trying to take wages off me when times were hard).