Wait how did he cut his hand on purpose? Did I miss something? ╮(￣▽￣)╭

Hey, so when the glass things fell and broke, his hand was alright but then he twisted his hand on the shredded glass which made cuts on his hands. If you go back and read when he fell you will see when they wrote TWIST which means he twisted his hand to cut himself. ( sorry if I didn’t explain it properly) :)

Thank you!! I get it now (●'◡'●)ﾉ