Did I overreact, or was this an autism meltdown waiting to happen?

I was hanging out with a longtime friend, just messing around, and we decided to try one of those “world’s hottest chips.” The plan was simple: we bought two chips, one each, and agreed we’d eat the whole thing.

I ate mine. Apparently, while I wasn’t looking, he only took a small bite of his and hid the rest. I didn’t know that until I stepped out of the room and suddenly heard him coughing then my dog started whimpering. Loudly.

I ran back in and realized my friend had fed the rest of that chip to my 13-year-old dog. He was smiling. Actually smiling. He immediately told me what he’d done like it was funny or clever, even while my dog was clearly in pain.

Something in me just snapped.

I slapped him and yelled at him to leave. I started crying uncontrollably, the kind of crying where your body takes over and you can’t regulate anything anymore. It felt like a full meltdown rage, panic, guilt, fear all at once. I gave my dog milk and stayed with him until he calmed down. He’s okay now, thankfully.

I blocked my friend afterward. I still feel sick and angry just thinking about it.

Here’s where I’m struggling: part of me feels guilty for hitting him, but another part of me feels like he crossed a line so severe that my nervous system went straight into overload. I don’t think he understood how deeply upsetting that was for me or that harming an animal, even “as a joke,” is a hard boundary I can’t tolerate.

So I’m asking this community:

Was this an overreaction, or does this sound like a justified autism meltdown in response to a serious violation? And how do you cope afterward when the anger won’t let go?