1. Why doesn’t the wife care that her husband found 2 million? Is this just bad acting?
2. How come nobody else was in the police station when Chigurh killed the deputy?
3. Why didn’t Brolin just get rid of the tracking device right away?
You should google what a plot hole is
share1. We just don't see her react. That would fit in with a lot of things that were not shown on screen.
2. It was a very small, rural police station. Probably only one officer on duty.
3. He didn't think to look for it. It was 1982, and it wasn't a James Bond movie where period are used to fancy gadgets. A tragic mistake, not a plot hole.