a guy went for my throat mid-swap without asking and im trying to figure out if i overreacted

wanna get this off my chest and see if im being unreasonable. im 34, dh is 36, in the LS about 3 yrs, mostly through a private group in birmingham. last weekend we met another couple at a hotel takeover, soft swap evening, vibe was lovely all night, they're experienced (in the LS like 8 yrs apparently). we got into a room with them, things going great, im on my back with him, and out of nowhere his hand went right to my throat. not light. proper grip. like he was clearly into it and assumed i would be too. i panicked. yellow-ed instantly. he came off it the second the word left my mouth, which is good, but the energy went and the scene was over for me. my dh was across the room with his wife and didnt see the moment. i didn't bring it up to the other couple before we left, just said "had a lovely night cheers" and went. in the car i was furious. by the morning i was second guessing — like, did i overreact, was it really obvious he didnt ask, did i give some vibe earlier that suggested choke was ok... my dh has been amazing about it btw, he says no the guy was out of line, but ive seen him in protect mode before so im not sure if im reading him straight. so — going-for-the-throat-without-asking, is that genuinely a boundary breach in your view or have i been spoiled by careful play partners and missed that some people just assume choke is on the menu. and do i message the other couple to say it wasn't cool or do i just not see them again and let it die quietly