Did anyone else notice...

Near the beginning, the short sequence where Balthasar is pulling the hay wagon, the wagon tips because Balthasar is pulling the wagon too fast and then runs off as a group chase him with pitchforks, and ends up back at the farm, reunited with Marie. Watching the film today for the 3rd or 4th time I noticed at the 7 minute, 34 second mark (on the Criterion DVD) A hand emerges from the hay and appears to be pulling the pin from the wagon hitch, being the actual cause of the wreck. I don't know how I missed this before, as it is shown in closeup, though the shot is only a second or two. Has anyone else noticed this? Any ideas as to whose hand it could be? Or am I missing something? Is it the wagon drivers hand? It appears to be a young woman's hand, mysteriously emerging from the hay. Could it be Maries hand? Any ideas?