Basically, there are many exploits on maps. Example : vsh_west_fix(under map exploit). When the meds are healing a (corpse thingy from the MvM gamemode) players can get instantly respawn in the base if they wait till the freezecam stops, then press decline while the med is still healing. Note that : even after the 1st death and revive, the player still gets another (corpse thingy from the MvM gamemode).