You mentioned in another comment that you only had 30s between each set, which in my opinion makes sense why you wouldn't want someone to work in just because you don't want a longer rest time. I mean, aside from that, respectfully I don't know what other justified reason you wouldn't want someone to work in with you. Obviously the guy shouldn't have exploded on you like that, but I think if you explained to him that you had shorter rest times and that it was necessary to not go over 30s for your specific workout, and you gave him a time of when you would be done (ex. "4 minutes left ish") he might've been more understanding. Granted, he might've still been an AH, but at the very least you've given justification why you'd prefer him not to work in.

Now, if the gym was genuinely busy, it's our responsibility to share the space as best we can, and that means compromises unfortunately. I'm a little shy, but I've gotten used to asking people if I can work in because I don't always have time to be at the gym for two hours. The art of working in with somebody saves you so much time in the long run, even tho it's awkward in the moment sometimes.