OK, I'm still just a nursing student, but I know a thing or two about how people work. It really sounds like it is one of two scenarios. One you might be able to do something about, the other not:
1. Someone doesn't like YOU and so they will nit-pick you and hang you out to dry for frivolous procedural points that everyone else does without criticism and use it as an excuse to ax you. This is because they don't have the maturity to work out a personal problem directly, OR *they* don't see it as a resolvable conflict. The only thing you can do about this is: "Let's be straight forward. I like to be compatible with everyone. It is key to teamwork. If my style and interaction is rubbing you or the unit the wrong way, let's identify that and see if it can be shifted to fit. Not everyone fits in everywhere, but I am willing to try."
2. Pressure from management... it is a bad way to run a show but lots of businesses follow this HR routine:
Management: "OK we need 6 highly skilled people fast. Go find me a dozen of the best cadidates you can and run them into the ground in a super short (cheap) crash course. We figure half will not make the cut."
Training: "OK, great news, 8 made the cut!
Management: "***** We can't keep 8 new employees! Get rid of two of them. Find a reason... make one up if you need to."
This HR style is common in business, but it is really only indicated for emergency staffing. Unfortunately it is used as a SOP and it quite simply screws over valid candidates, souring them from working for that organization again. This hurts the company too, as does the training results of the crash course, even with competent candidates!