most time if you push the shifter into reverse doing 25+, like Jani said, the tranny will realize that there was probably a mistake and just keep you in neutral. Ive done it a few times on my car too that why i know.

but in any event, if it did shift, some one told me you can get a new tranny or just a new reverse gear, but getting a new tranny was more worth while...so choice is yours