Yes and I rarely see them leak. It's usually the rear band pin seal and it'll look like it's the extension housing gasket. You wouldn't believe how many times I've torn apart transmission that were supposedly rebuilt only to find their idea of a rebuild was to just pull the clutch packs and install new clutch discs and slap it back together. Not saying that's what was done with yours but it could be
The guy that did the work closed his shop and skiped town on me. He was a crook and a dangerous guy in the end. So I have no recourse and no idea what was done with the trans. I don’t think much unfortunately.