Character mistake: There is a level 1 sentry on the back of the blue truck Engi is sitting against. This sentry is closer to the ridge that the Sniper is on, who is trying to sneak up on Engi. However, it is the level 1 sentry beside the truck next to Engi that reacts and kills the Sniper. The truck would have been between this sentry and the Sniper, so it couldn't see or shoot it, and the sentry on the back of the truck would have seen and shot the Sniper first. (00:00:35)
Character mistake: When the Level 3 Sentry gun is revealed on the right of the screen and fires a rocket barrage to the left, you hear it explode as the Engi looks over. You then hear Scout scream "My arm!" really loud. Then an disembodied arm falls in front of Engi with a plop. However, this arm is from the character model of Sniper, not Scout. Including his glove and his watch. (00:00:45)
Character mistake: As the camera pulls back from the truck, the Level 3 Sentry on the ridge looks up and fires rockets into the sky for no reason while the enemies are advancing from in front. Sentries specifically target human movement from the enemy team, and there are no rocket jumping Soldiers or sticky jumping Demomen off in that direction. The sentry is just shooting at nothing up in the sky. (00:01:10)
