How would you react if you accidently saw your friend's genitalia on video chat, and they didn't know you saw?

I recently had this happen. My dearest friend was video chatting with me, and she thought she turned off her video at the end of the chat. but, it didn’t, and i saw her urinating and performing certain female hygiene things. I KNOW she didn’t do it on purpose; and she has a BF. What should i do? Should I tell her I saw it? I mean, it’s lovely and what not, but i feel kind of guilty. What would you do? Has this happened to you before?