Why doesn't Buddy help me survive the Ambush in in City 2?

Solution 1:

You need to shoot the chandelier blocking Buddy's path before jumping down.

When you first enter City 2, you can spot Buddy in the crawlspace below the floor. He tries to move forward, but his path is blocked by a hanging rope.

Head to the bottom of the staircase with the teleporter, where you were previously surprise-attacked by a guard. From this staircase, keep heading left for 2 rooms until you see three hanging chandeliers.

Walk up the stairs and shoot the lowest-hanging chandelier to clear Buddy's path.

Shoot this chandelier to free Buddy
- Image courtesy of Visual Walkthroughs