I’ve seen it in person. I play multiplayer, and I watched my friend pillar up concrete. On his end, he was just pillaring up without issue, but on my end his character was constantly dropping off the side, presumably from clipping with the block he placed that loaded into the game before his jump registered. This is what’s causing the random damage and sometimes the glitching out the sides of pillars. The game registers the block placement but doesn’t yet realise you’ve jumped, so it shoves you off the side. Sometimes the client corrects the server in time, and you’re put back onto the pillar, but sometimes it’s too late and you’ve fallen off. Usually the damage registers anyway if you’re close enough to the ground.