Yeah, I saw that too, via a retweet from Mato. It was the webmaster of a site called Tuxedo Unmasked. That person also pointed out errors in the intro sequence.
This is the thread in question about the "clown" mistranslation.
Here's the beginning of the playthrough/comparison that prompted the "clown" example, but they're not linked in a single neat thread, and I don't want to post a link to every tweet.
Yeah, we fixed that pretty early on, along with the intro.
Another interesting thing that got lost in the old translation was an on-going gag with Minako messing up proverbs and someone correcting her. There are several instances of this in the Japanese script, all but one of them (AFAIR) glossed over in the BST patch. We've done our best to restore that and localize it as something that doesn't stick out like a sore thumb.
Speaking of Minako, one of her lines near the end of her chapter was changed by BST to have an Artemis avatar, for whatever reason. Probably to make it flow better?
Another interesting one is how in the BST patch two Tokyo NPCs say almost the exact same thing: "If you go east from here, you'll reach the Hikawa Shrine. And west of here is Juban Hospital.", but the second one in the original is in fact an observation on how it's weird that even though Mugen Academy is defunct, there is still a bus line going there. This might've been a localization decision, since the reference to the Sailor Moon S would've been unclear to the casual fan at the time.
Or there's one you can spot just after leaving Usagi's house: the middle-aged lady in the neighborhood. In the BST patch she says she'd like for Usagi to meet her son, who's very handsome. In the original, on the other hand, she mentions seeing Usagi out with a cute guy, with a wistful comment to the effect of "If only I were 10 years younger, you'd be in for some real competition". Maybe this seemed a bit creepy and desperate, so it was changed?
But to give credit where credit's due, BST did expand the explanation about the True Stones, elaborating on how the Four Heavenly Kings used to be Endymion's servants before becoming Beryl's lackeys. And they included a funny reference to the DiC dub and Makoto's... talent. Hacking-wise, the BST release was solid, only marred by the intro text glitch that I've fixed. And they did translate all the signs in the overworld. It was also one of the first SNES patches to implement a VWF, if memory serves me right. This alone was a monumental achievement back in 1999.
As you can see, there's lots to talk about here. And if you're hankering for more, Tuxedo Unmasked announced they'd be doing a thorough comparison of the Japanese and BST scripts in the near future.