Wow, good catch! Thank you very much! I had not fixed it, as it turns out. It's fixed now! This is a very old bug - I've never been able to replicate it, so it was hard to track down.
The engine doesn't do any real compilation (just JavaScript JIT compilation) - I'm guessing there's probably a cache or something that makes the error persist on your machine after you fixed it.
The fix probably won't be in the public version until 10.2 or 10.3, but it's coming. Thanks again!