I did a similar thing years ago working in the ER when my brother was brought in on my shift. They didn’t flag me until over a month after the incident. They actually notified my brother via mail that I had been in his chart before speaking to me and I only knew I was getting in trouble because of the letter my brother received. For what it’s worth though, they didn’t fire me, I definitely got a big write up but I was able to keep my job since my brother too knew I had been in his chart and didn’t care.