I’m scared a failed a think 25 test purchase.

I work on the csd and a man came up with 2 food items and got a vape. He did look young but still thought he was a couple years older than me. The only thing was he was quite small. I’m 23 btw. The only thing that made me re think about his age was he asked for a receipt which for a couple times people don’t normally do. We had a test purchase about 2 weeks ago. But the girl who passed it found out straight away. Is there diffent types of test purchases that I wouldn’t find out straight away.