I want opinions on who you guys think is at fault because at the time I was a bit puzzled but afterwards asking multiple people, I feel that the semi-trailer was in the wrong and should be held responsible. However, these people clearly have a bias in the situation so wanted unbiased opinions.
So, it is a TWO lane roundabout. I had entered the roundabout and was doing a full U-turn as I'm like ¾ of the way onto the other side, the Semi-trailer (coming to my left) starts entering into the roundabout (remember two lane roundabout) so I assume ok that semi-trailer is turning left (furthest lane) into the same street as me because that makes the most logical sense + I was already in the roundabout so I have right of way + I can't just slam the brakes when there is possibly a car right behind me + he was leaning towards that side. So I stay on my lane (inside lane) turns out he is going straight actually and hits the the back left side of my car (Where my rear left light is).
That's the important information, the rest is extra.
He gets out maybe not aggressive but irritated for sure, called his boss and he seemed to be a pretty chill guy. Another guy who is driving a smaller truck stops and says I'm at fault because I was going "at least 80" (even though I literally U-turned staying in my lane, my car isn't a Ferrari or even Toyota 86 so the acceleration isn't that good) and if I'm being 100% honest, the guy (the 'witness') was honestly a massive jerk and kept egging the the Semi-trailer guy on pretty much. The Semi-Trailer guy says he didn't see me, I realised this after but I don't think he knew I was doing a U-turn and thought I came from the lane on his right. He kept saying he had "right of way". I was already in the roundabout before he even approached it.
The unfortunate part is that he had a dashcam and I didn't….so all you'll see is the hit which he can argue that he entered the roundabout first (which obviously isn't right at all). I'm thinking about going to the local businesses nearby and hopefully one of them has a camera that shows their parking lot, which hopefully shows a bit of the roundabout.
Obviously this is only one side of the story, so maybe the Semi-Trailer guy has another side that would make you change your mind.
However, based on the information, who's in the wrong?
Do you have insurance? Leave it with them to sort out who is at fault and not an online community whose opinion has zero impact on the outcome of the situation
FWIW based on your info you were in the right because you were in the round about first