In my opinion, it all comes down to the host (Milsim or run and gun games).
Now the host(s) can’t watch the whole field at once, and not give away players position, so select (trusted) players (paintball ref, for run and gun) should be put in charge of keeping an eye on the section of the field they are in/playing. ‘Select’ player(s) shouldn’t be a friend/teammate, of host, unless respected by players of that game. If these players are kept a secret, beside other ‘selected’ players, then it’ll keep the rest of the players on their toes.
For the players that don’t ‘feel the hit’, because of bush or layers of kit, he/she should look at the situation around them.
For example: there was one game, at Flagswipe, that I got behind a group of enemy players and emptied a full mag on 5 of them. There was another player, behind tree/bush, that killed me witch lead to a min of quite as we sorted things out. I can’t remember all the players name, but Sha Do was in his guille suits second furthest player from me, everyone raise there hand and called hit. Sha Do turned to me and said (something to the effect of) “did you hit me”, I’m 95% sure I did (maybe I just hit the guille fabric), I said “yes” and he then followed suit and we all walked to side of the field to let the rest of the players play on. Now maybe Sha Do had too many layers on, or maybe I didn’t actually hit him, I respect the fact that he didn’t argue the call and took the death like a man.
We all need to remember this is just a game. If it’s a run and gun game 5-10 minutes later, depending on size of group and game type, everyone will start a fresh round and shouldn’t be calling other player(s) hit or not calling their hit. Now for Milsim game you may spend an hour crawling to a key spot, only to be shot by another player (stray shot), then you should take note and improve you tactic/skill.