My partner [F25] got mad at me [M25] because I put her water bottle in her bag instead of in the side pocket, which could have ruined her electronics and papers inside. What should be done?

Hello,

I was helping my partner get ready for school this morning because she was running late. She asked me to put her water bottle (metal one with a lid) in her bag, and so I put it in the main pocket area where her iPad and other papers related to school were. I thought this was kind of a weird place to put it, so I did screw the lid on tight but I didn't double check with her. For context, she was running on less sleep than normal and also having a stressful day. We have been dating for ~4 years.

After I dropped her off to go to school, I got home and got a text from her where she was swearing and extremely upset at my ignorance and recklessness for potentially destroying her important stuff. She said this was a bad sign because if I am reckless once I would be reckless in other scenarios. Usually I would just let her cool down and we would talk about this later. But she said to ask my friends/reddit what they think about the situation.

I think I should have probably confirmed where she wanted it instead of assuming inside the bag, and I understand how terrible it would be if all that stuff was ruined. What should we do about this scenario?