Is 202 appropriate for the error code on this video? 201 seems more correct for a normal web app.

First, let's clarify that the 200-299 are not 'error' codes, they are server response status codes expressing the success of receiving and understanding the requester request and a server action has been taken. Then they must provide some feedback information of the server action about the client specific request.

But still you have got a point here, as per the video, the 202 means the resource has been created as per the request, which it is not, that would be confirmed by the code 201. 202 is more like the server responding to the client with : noted but I will process your request later, you do not need to maintain/persist the connection. And it must also clarify how it will notify the requester with the final status of the request to create the resource. For more specific standards on all codes including more detailed quoting of the standards on these two codes you can check the official w3 protocols here :

https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html

And for information about the W3 itself, the community setting the standards for the web, including the standards mentioned above, and is led by the inventor of the web himself, Tim Berners-Lee check :

https://www.w3.org/Consortium/