I hope someone else is still playing this game and can help...

Every time I try to listen for the code and fire my sticky cam - NOT the diversion cam - I get an irate Lambert and a Mission Failed. I have shot it, in the final opportunity, after the dog ans 2 guards scene - into the wall, the boxes, the truck cabs, the truck sides, the ground, anywhere and it fails. Did I shoot too late or too early, maybe? I tried at other positions and same happens.

Any ideas what might make it work so I can move on??