Background: I have a 2 year old, sterilized female Siberian cat. My mom's taken care of this kitty for weeks on end in my apartment while I've been on vacation and they love each other a lot. There's never been any issues.
So today I brought the kitty to Mom's place and it didn't go too well. Initially the cat explored the apartment and gradually got more confident, even eating some treats from my hand and sitting in my arms calmly. She also let my mom and girlfriend pet and lift her. But then my mom opened a cupboard to take out a water bowl. The cat instantly wanted to go inside the cupboard, but Mom lifted her out and closed the door. So the cat meows loudly, growls and hisses, then backs Mom into a corner. No claws or bites involved.
After this Mom couldn't get close to the cat without the same thing happening again. We brought the cat home and now she's relaxed again. So my question is what happened here anyway? Never had this kind of reaction from the kitty before. Any steps I should take to not lose my best catsitter? =P