In the left hand turn, with that amount of bank, the P-63 was blind to anything outside of his turn radius. He wouldn't have seen the B-17 until immediately before he impacted at the trailing edge of the wing/fuselage join and sliced the tail off the B-17. With no tail, the bomber just nose dived in. It was all over for everyone in less than a couple of seconds, the P-63 was probably reduced to debris after the impact.
The rules of the air dictate that when converging with an aircraft from the right, you give way to the right (the B-17) but of course, that assumes you know there is something there in the first place. It was the P-63s pilot's responsibility to clear the turn, but what was the ATC status in all this? Was there an Air Show frequency? Was there positive control of the display, had it been rehearsed and briefed to a display coordinator? Or was it "turn up and give us a show?". The real tragedy is that when the accident report is finalized, it will not contain a single new element that couldn't have been cut and paste from many of the previous Air Show collisions.