Halo 5 Warzone Assault glitch?

I was playing Warzone Assault on Array and the enemy’s captures the armory before capturing the spire. We almost won the game around 2 minutes left and they reset the time by somehow capturing the armory before capturing the spire. There was no indication of them capturing the armory. i went into theater mode and found that a player was slowly capturing the armory by going up to the shield door and ground pounding the corner. I have posted a video on Youtube if you want to see it for your self. (- YouTube)

I’ve got this multiple times and its REALLY annoying if your defending