During the teleporter puzzle, I had a lot of random deaths due to physics glitches. When standing on the moving platforms, I would randomly die if I was standing too close to the railing on the back of the platforms or the little nub on the front of the platforms. I believe this is due to the platforms causing instant death if they hit you, and it sometimes detecting a collision with the features on top of the platforms.
I can confirm this glitch. I had no idea how I was dieing, as I was safely riding on the platform from what my eyes could detect. After multiple reloads, this problem remained. I had to ride the Lambda Reactor very cautiously with plenty of quicksaves. The platform that appeared to have the most deaths was the very first one at ground level, that allows access to the 01/02/03 portals.
Also adding my confirmation. It seemed to crop up mostly when I was standing or crouched towards the back of each platform.