RECOVER DVD - Power Failure Sony GX7 ?

[johnnyelectron]

Help please.
I recorded a school function with a camera plugged-into a Sony GX7 DVD recorder (with an audio mixer going into the audio, the camera feeding the video). I recorded to a DVD+RW. All was fine and good until 1-1/2 hour into it and the principal pulled the plug on the Sony DVD Recorder. After the blood rushed back to my head, I realized that now I have nothing on the DVD+RW disc. Is there anything else I can do? I did record about 15 seconds onto the disk again to see if that would help it record a 'directory' or something, but all I have is 15 seconds of crap with the hour and a half of A/V missing.
I have tried DVDdataRecsue and a few other TBYBIT programs, but nothing appears to be there of any size worth buying the program for.

Should I have just waited AFTER power was restored to see if the Sony DVD Recorder would automatically do a 'recovery' of the data and write it to the disc?
I know that my standalone Philips audio CD recorder will at least do a default where you can still play the disc on only that recorder long enough to dump it into another recorder, do the Sonys do the same RECOVER automatically?

Should I not have recorded on the disc again?

Do the Sony GX7 recorders have a way to recover disc data in a power failure?

Is a DVD-R (or DVD-RW) a better choice for my "live" recordings than a DVD+RW?

All suggestions would be appreciated, as I cannot replace the missing recordings of the kids at school. Thanks.

[Krispy Kritter]

Since the recording wasn't properly completed, there is no way of recovering the data.