what run group is this in? If its a novice or instructed intermediate group, I take slight issue with you and slight issue with cayman driver.
your beef: You came up on this dude pretty fast and I would guess he's a novice who is barely capable of processing getting his own car around the track. As a result, if I was your instructor, I likely would have told you to give him a bit of room going into the turn. Hard to tell from the video just how hard he slammed on the brakes.
His beef: the cayman driver should have been aware that you were closing behind him and if he wasn't, his instructor should have been. As a result, as soon as he got out of shape and recovered, his hand should go out the window to let you by.
If this was in a black or red run group, it would be a "sorry I went by you without a point by, but WTF were you doing out there?"
Without knowing what everyone was thinking, I think this would be chalked up to a ******************** happens, nobody got hurt, just give each other a lot of space our there, and move on.