my dog bit me

Hi, my 9 month JRT actually bit me the other night and broke skin for the first time. She had grabbed a potted plant and left a trail of dirt from the dining room to the living room - behing the sofa (her favorite spot to sleep). I called her name and moved the sofa while she was behind it and I *think* it startled her so much that she lunged at my hand and bit me.

I don't know if she meant for that to happen because he was completely terrified and I know she felt bad afterwards because she was shaking and ran away as soon as I reacher over to touch her. I put her in her crate for a time-out period because I think it was an accident.

She is a mouthy dog and usually play bites when she is excited - I just don't know what came over her last night. She has been through obedience school when she was a younger and has been spayed.

Is the time out a correct punishment? My boyfriend said I should have ignored her for an entire day. I'm wondering what to do if there is a next time, but hopefully there won't be a next time.