Other mistake: Walter's pants flying in the air defy the laws of physics. The RV is racing forward and the pants somehow find themselves in front of the RV floating through the air. One could say that the pants perhaps flew forward when the RV 'hit a bump' perhaps. However the RV would have to hit a considerable sudden stop to get the pants to fly forward. The RV then runs over the pants which have fallen to the ground from in front of the RV. This could be ignored as somehow possible due to some strange anomaly. Except near the end of the episode. We see the same pants fly off the mirror of the RV flying backwards. Making it impossible for those same pants to be run over from in front of the RV especially due to the speed at which they are flying backwards straight into the camera shot. (00:00:15)
...and the Bag's in the River - S1-E3
Other mistake: Walt pushes water jugs and several items toward Krazy 8 who is locked in the basement. Notice the ground has been disturbed where the jugs slide, indicating previous takes.
Chosen answer: It is part of the ritual for la Santa Muerte. It is a sign of humility and sacrifice.
djm