Armadyl boss glitches?

So i went to armadyl dungeon killed the boss i went back out the door for a sec, then the arma boss spawns again and flys through the door, then i run away and i follows me to where you use the grapple?

Lol if you could do this with bandos boss to you would be able to get it all the way to the centre/intrace of the gw dungeon.

So i guess its a glitch lol i thought i just going to post this.

Lol kinda nice actually