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.

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.

No expectation of privacy in public and video can be taken. For example, security cameras that also happen to capture audio.

in which jurisdiction? Just because there's a device that breaks the law doesn't make the law go away.

Katz v. United States (1967)

Glik v. Cunniffe (1st Cir. 2011)

I don't see how either of those cases apply to regular people making recordings of regular citizens (in public, or not) using a microphone.

I was referring to video with a camera which has a microphone

As was I.

But to extend the context: I don't see the relationship of either of those cases to anything being discussed here at all.

Drive thru conversations are not private under the Katz test, so there is no reasonable expectation of privacy. That makes video or audio recording in that setting lawful.

Katz came about because the FBI recorded a gambler outside the booth with the doors closed. Hence we have the Katz test.

Heck, you can even record someone making a drive thru order yourself and no one can do anything about it

If the question was about whether a warrant would be required to record a person at a Burger King drive-through, then sure: I'd bite.

But that kind of question does not appear to be related to anything in the context of the discussions here on HN.

You seem to have presented a red herring.

Not a red herring. The Katz test defines when a conversation is private, and a drive thru order does not meet that standard, so recording there is lawful even when it is done by a private person and not by law enforcement.