Sure, that’s definitely an option.
I feel that being able to control some UI elements programmatically could be kind of useful though. This API can’t be the only one misreporting its Content-Type. But I don’t have really, really strong feelings about it.
Perhaps you could like set “pretty” and “JSON” for a saved request and just have it always try to use that setting no matter the content-type, rather than having to reset after each call. Or even if it could be a bit more intelligent about “this looks like it’s JSON”.