When Tim and Leonard exit from hiding in the storage closet, the closet door is left ajar. A few minutes later when Leonard is checking for the guard, a shot of the staircase shows the closet door closed. When Tim and Leonard return to hide, the closet door is ajar again.
In the opening scene, when Tim (Radcliffe) looks into the skip dumpster, it is full to the brim: when a few seconds later he returns to place the carrier bag leaflet distributor explosive, the dumpster is now clear where he puts it in.
When testing the broom handle used to unlock the outer door, the handle barely reaches the keyhole. But the same handle is combined with a rotating mechanism which would require the handle to go beyond the center of the keyhole to turn the key.