When Fitzhugh takes the razor blade, matches and radio from the giant, he lays each item to his right in the box. When the giant is wrapping the box, the items are all to Fitzhugh's left. Moments later, when Captain Burton does the radio test, the items are all back on Fitzhugh's right.
The envelope is set on fire on two edges but in the next scene the fire is only on one side and the other side is unscorched.
Barry has Chipper with him in the forest before he and the others enter the vent but Chipper is not with them after they go in and is not seen with them afterwards.
Between two consecutive scenes, Fitzhugh changes position while in the box. This is while the box is still not when its being moved and he is knocked about.
The pencil Gorak takes from his pocket has a noticeably sharper point than the large prop used to show it pointing at the miniature map.
When Fitzhugh takes the razor blade from the off-camera giant, the shadow of a human-sized hand can be seen releasing it.