Raz managed to find the chute... but it wasn't on the HQ building... it was on the Inspector 2, and he was in a ventilation shaft, not a garbage chute.
As the Inspector II started up, the ventilation did too, and Raz was sucked through the shaft and as he flew through the shaft he screamed, he then saw the pair of blades that forced the air through and he quickly approached them, that is until he was shot down through a vent grate and right into the cockpit of the Inspector II, right behind Mary.
Multiple times before, Raz had been told never to go into shafts or chutes as he could get himself hurt one day, but he never listened as he found the tight spaces to be cozy. A few times before he had gotten hurt, but not badly, such as when he fell down a 1 story vent and broke a forearm. It took a few days for them to get Raz out, but he made a full recovery... but he forgot the whole thing the next day and tried to do it again... they blocked the vents the 2nd time it happened.