Comment by xmprt
Really good players can get lucky pretty often because of game sense so even glass walling is hard to detect for certain if a player shoots through walls and kills their invisible opponent. We see this often even in pro play for tactical shooters.
Yup, At top level play, players know the games and the maps so much that they can get some kills through walls just from knowing that its is likely that an opponent WOULD be at the other side at second X after seeing/hearing them at second Y.