Combined probably about 50. He hit the brakes pretty hard before hitting, wiped a bit of speed at least.
Ironically, his mistake was what kept him alive. A better rider would not have locked up their front wheel like he did, hoping to just pull the turn tighter, but ironically that might have killed them if they hit the side of the truck instead at higher speed.
He didn't lock it up - the bike has ABS. You can see and hear the ABS actuating (handle bars twerking and tire chirping).