To me it sounds like she was playing. Was she grunting or anything?

I agree with sarah, it sounds like playing. An upset bun would for example growl, box and/or nip or even bite. Buns can make it very clear when they do not approve.

My buns get stroppy if I move their hay, they do not get aggressive but the looks on their faces and body language is hilarious.

Back when my girl was a lone bun, she used to sleep in a cardboard box to avoid the summer heat. One day my Ex decided to do the crawly spider fingers. My bun attacked him and drew blood shes a clever bunny! Knew before me that he was a dud :p Anyway – my point is, if your bun was being upset to the point of aggression – you would know about it

Fernando has taken up a new game lately – nipping and pawing at my clothes and feet. He started out with my undershirt, but nowadays he favors my feet/socks. Maybe he likes the smell. He’s definitely being playful, with a side order of “move your feet so I can move around more!” and “hey, you big lunk, pay some attention to me!”