There's always that one kid who decided to play this game even though he doesn't have a mic. After the first stage, you can catch the kid who isn't talking away from everyone else and start shooting him. Then, reload your gun. Since he can't speak, he will most likely just start shooting back as you are reloading. This is the time to shout really fake things like "this guy is shooting me" "stop it" "ah", and nobody will know that you fired first.

A simple thing to do too is to just throw the conversation of "this guy isn't talking" out there into the open, and if your group is meme enough, state that "he's probably talking in infected voice chat oooooooo"

You can also say you someone is your brother/friend irl and he's infected or something stupid like that and say he's infected if you're that evil

Also, try drinking a blood bag right in front of the person without a mic when you catch them alone, which will probably cause them to shoot at you which is when you can do what I said originally

This should work on people that are level 3 or below

The good thing about the G key is that barely anybody uses it. If you are infected and you scan an innocent person, hold down G and select the "this person is infected" option while aiming at them.

New players will think that the scanner automatically says if the person you are scanning is infected in chat, and shoot the person you were scanning.

On the first stage of the Arctic map, upstairs in the corner there is a stack of wooden boxes. You can crouch jump onto both boxes to get to the top, revealing a secret spot to hide. After a few moments of getting the objectives around the map, tell your team that there is a secret way to get up to an unreachable spot. If everyone goes to it, you can leave and drink blood bags (because trust me, if i fail the jump i will keep trying again until i finally get it)

Some players, once they make the jump, will choose to stay up there (which will make them unreachable, but that shouldn't matter anyway since the fuses will not be put in the power boxes, and will stall them)

This is not recommended, but if you are in a really strong edgy meme group of players you can say "this guy was just looking at the bloodbag i think he's infected". I've been in games when people took the game the opposite of seriously where they would just kill the person who you said was looking at a blood bag.