Grunt Despawn Problem

[Shadowfied]

I'm working very hard on my custom story, Castle Darkuan, and I have a kind of problem in one part of a map.

I have a room in which there's a crowbar, when the player picks it up, a 5 second timer is activated. When the timer is out, a grunt spawns and comes towards this room. I hate it in custom stories when the player is forced to get killed. I prefer it when the player must hide and wait for the grunt to disappear. I have it all setup, but there's one way to abuse it very hard.

The player can't pass the grunt after he is spawned, cause it's a very small / thin path and there's no room to run around the grunt. However it is possible to pass the grunt when he is inside the room, if he starts chasing the player, he will enter the despawn script area and disappear. I don't want him to disappear when he is chasing the player, or if the player is watching him.

Any tips on what I can do to prevent this?

Thanks in advance.