Visible crew/equipment: When Jesse gets into his car the second time, a boom mic is reflected in his door. (00:09:40)
Visible crew/equipment: When Tuco shouts "Yeah look at this" the camera cuts to Jesse and in his sunglasses you can see a crew member reflected. (00:03:40)
Visible crew/equipment: After seeing the photo from Hank, Walt runs into the kitchen and grabs a gun. Jessie then comes in and tries to grab it from Walt. Pay attention as Jessie runs in. A pink T marker is visible on the floor. Slo-mo helps, but is not essential to spot this mistake. (00:37:40)
Crawl Space - S4-E11
Visible crew/equipment: A camera in a black protective box is visible on the ground in the intersection during the crash sequence when Walt gets T-boned by an SUV. (00:24:48)
Chosen answer: It is part of the ritual for la Santa Muerte. It is a sign of humility and sacrifice.
djm