I Spilled My Drink All Over the Guy Who Always Comes in Late and Talks Down to Me Every Night

Okay, so I work as a bartender at this swanky new spot downtown. I mean, it's not really that fancy, but it has some decent beer and cocktails and we get a lot of college kids and young couples looking for a place to unwind after dinner or drinks elsewhere. But there’s one guy who comes in every night around midnight, yeah, late, like he knows the real party starts after everyone else leaves. He usually orders his drink and then stands by the bar with that superior look on his face, talking about how I don’t really know what I’m doing behind this counter and how much better his bartenders are elsewhere. I’ve tried to ignore him most nights, but tonight was different. We had a big night of people in here for trivia and it got super busy with groups coming and going all evening long. By the time he showed up, we were running short on ice, which means refilling drinks is taking longer than usual. So there I am, trying to make his drink as quickly as possible without cutting any corners on quality or presentation because that would just give him more ammunition for another night’s ranting about my abilities. But then comes the moment, while I’m pouring one last cocktail, a bit of water from condensation drips off the glass and hits the drink I was preparing right beside it. The splash makes me lose grip on his drink, sending half of it down the front of his expensive shirt. Now, if you’re thinking I should have apologized or something, well, let’s just say I didn’t feel like being diplomatic tonight after all those nights of him putting me down. Instead, I looked at him with a grin and said something along the lines of 'Oops! Better luck next time!' He was pretty stunned, to be honest, no one had stood up to him before. So here’s my question: Is it wrong that part of me felt like I finally got back at someone who never thought twice about being nice or polite? Am I really the asshole for not showing more remorse when he left red-faced and dripping wet, complaining to the manager who only gave a shrug in return? What do you guys think? Did I overreact, or is it okay to stand up for yourself sometimes?