Plain text wouldn't be better in that case, but then I'd know it was corruption instead of questioning if there was a spec change and trying to find a compatible piece of software that would still open it.

RTF is a textual format. You can open it in a plain text editor to see whether it's completely trashed or not. If it isn't, then you can even recover the raw text from it without too much difficulty.

In that case, it was corrupt. I did try opening it in a plain text editor. Some of the file was there, but not the whole thing.