Hand washing in school bathroom, lack thereof by fellow adult!?

All she does after she comes out of the stall is quickly dips just her fingertips into the faucet stream, turns off faucet, taps excess water off of fingertips on edge of sink, then leaves...no using of soap, no towels. I witnessed this in person. Did not know what to say or do. But I feel like I should do something if possible b/c she is a secretary and brings in baked goods, and has student workers, this is at a high school. I am grossed out. What should I do? People can get sick from this.