Finalizing an unfinalized DVD-R?

So a few weeks ago I was on TV and I decided that it would be cool to share that with all my friends. I saved the show on my Toshiba DVR and was able to watch myself repeatedly make a fool of myself on TV.

I burned a bunch of DVD-R discs and sent them to my friends overseas. In the past few days, messages have been trickling in from these friends. The DVDs don't play.

I did some searching for the possible reasons and it dawned on me that I didn't do any finalization of the DVDs, so they are unreadable on other players. For some reason, I figured the recorder would automatically finalize each DVD at the end of recording, so I didn't even think about doing it.

Is there any way to recover those discs, which are all overseas now, using some PC software? I saw a comment posted in another forum that recommended Isobuster, but their site (which is chock full of information) doesn't address this problem, at least not directly.

I would like my friends to be able to watch the DVD without having to reburn and resend new discs. Is this possible?