Burning players can activate linedefs
From DoomWiki.org
In Strife it is possible for the player to move around for a short time after dying when their death involves a fiery object as the inflictor of damage. The player's weapon goes away and is replaced with a pair of burning, waving arms.
During this state, changing weapons and using inventory items is impossible. However, activating cross-over and push-type linedefs is still allowed excepting one single type of line: the normal hub exit that passes the player seamlessly between two maps. This trigger is the only type in the game which actually checks if the player is alive before allowing activation.
This fact, inherited from the Doom engine and exacerbated by this modification, means that dead players can sometimes cause interesting effects on the level. It also enables another more serious glitch through which sequence breaking can occur.