I heard a recent interview with the writers and they were being asked similar questions. Essentially they said something to the sort that we all know what Walt CAN do. This fucker can do ANYTHING. So by the last episode they didn't think it was worth showing him in his car with 1000 fake sugar packs fucking them up until he got one just right or sneaking around a back yard making distractions. We know the dude can do it. He's Walter god damn White! We've seen him hijack a meth train, rid of bodies, take out a national drug lord, destroy evidence with a magnet, I mean what else? We don't NEED to see it now. It's not about that, we know what he CAN do, now it's about what he's doing as a person.