Callahans Crosstime Saloon

Here I am trying to keep a robot from Noah's back but I am not succeeding. Shooting him with the laser does not do a thing. Can some one give me a hint?

Hi Milo, fancy meeting you here. I know where you are because I just finished that sequence. Put your cursor (arrow) on the walls around Noah until you see the word BULKHEAD...take the laser gun out of inventory and shoot at the BULKHEAD which distracts the robot and you and Noah can escape it. OK?
Hi Witchen. Hope you are having a wonderful day. It sure is hot here today (and the last 3 days). Hoping the Delta Breeze kicks in for tomorrow and the weekend.
Love, Betty Lou