Is that even legal?

Here's my dilemma. I get back from first break and nature calls. Number 2. So I go to my station sign in scan an item then head towards the bathroom. I do my thing and later on in the day I get a talking to from a manager saying I took a 39 minute break. I told the manager what happened and he said, "You're only allowed 2 bathroom breaks outside of your break times and no more than 5 minutes." So I guess I'm looking at a write up for that.

Update: After having them review the video I was only gone for 12 minutes. Not sure what happened with the computer system.