Well, IMHO, that nurse should of never touched that fistula. That is the patient's lifeline. The ER should have never started the drip there. They should of got peripheral IV access and leave the fistula alone. If peripheral IV access could not be obtained, than this patient needs a central or PIC line stat.
I would never run any IV fluids through that fistula except in a code situation when no other access could be established.