@Karen2478 It sounds like an honest mistake, the host apologized, changed the code and it sounds like he is trying to make amends and making you comfortable. Why would you report this?
Sometimes guests do something that disturbs hosts, sometimes it's the other way around. Unless it's something horrible, and there are apologies and it doesn't happen again, I would give the other party the benefit of the doubt and not concern myself with it further. I've had guests who overstepped some boundaries before- I talked with them, they apologized, and it didn't happen again. Why would I run to report them to Airbnb?
People need to learn to cut each other some slack when someone makes an unintentional mistake.