The cowboys are a sloppy team. They have been so for a very long time. I'm not sure if there is ref bias as much as anticipation. Connor Williams likely has a rep at this point that gets him more ref eyes looking at him. While some of the calls on him are ticky tack, many are blatant. The same goes with the pass interference. Is it really that hard to tell your DB's to turn their head? If you run into a receiver with your arms up staring at his face, you are going to get flagged. Dallas does it so much that (IMO) refs anticipate it.
Personally, I see this as an aspect of the Jerry problem that is really the root cause of the 25 year stretch of playoff failure.