[nerdsniper]

Edit: Apparently some states do ban non-consensual audio recordings in public: https://www.dmlp.org/legal-guide/massachusetts-recording-law

The laws prohibiting these recordings have neither been upheld nor overturned by the US Supreme Court.

[EvanAnderson]

I wouldn't chance it. Stick an "audio may be recorded for performance evaluation purposes" on the drive thru kiosk and call it a day. Otherwise you're inviting litigation when something like this happens.

You can want things to be black and white but litigators are going to argue.