Due to the support you used there is a thermal gradient across the board, and the sticker wrinkled and seem to have pulled the chips.
1 wasnt me, just a dude on a computer forum I tried to help
2 support looks as good as you gonna get, from the looks of it it is a cake oven
there are no cracks, this module has 8 chips (or maybe 16, no picture of the other side)
It was totally my fault

. I told the guy to support pcb on the corners so chips dont touch anything, I forgot/didnt occur to me some pc memory modules have those stupid stickers across multiple chips. This is one of those things you do automatically without thinking when reworking smd (glue, stickers, plastic, spacers).