Continuity mistake: When Walt asks for the RV to be destroyed, there is tape over the bullet holes on both the inside and the outside of the door. However, when Hank is showing the bullet holes to the owner of the lot, he takes the tape off the outside and the light shines on Walt. No-one has touched the tape on the inside. (00:28:50 - 00:36:00)
Green Light - S3-E4
Continuity mistake: When Mike and Saul are listening to the tape recording, the recorder is on a join of 2 pages. We then get a close up of the recorder and it's in the centre of a page. (00:05:35)
Chosen answer: It is part of the ritual for la Santa Muerte. It is a sign of humility and sacrifice.
djm