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.

High level Q3 games had a lot of predicted movement kills for ages, long before vision automated aimbots. I'm not sure how anyone could even distinguish a perfect reaction there from a predicted shot that worked out.