Thanks for looking that far back, I was certain at some point around then I had been dealing with un-encoded tweets, the bug has only just been noticed in our software. I even recall TweetDeck having an issue where they allowed javascript to be executed.
While I am happy to incorporate a HTML decode if that is the intended scenario, it feels wrong to me as I’d like the unaltered text of the tweet, this is transforming it and transforming it back again, that’s not guaranteed to have the same text. But if it’s safe to do so without getting text incorrect then that’s what is required.
If that is also the intended usage, the API tool could do with being updated to stop hiding the issue and the documentation could explain what it is expecting to return. This would really help people going forward coming to the API documentation/tools.