That alone tells alot. I'd never trust laying a bare disk directly onto a desk surface (or directly on anything really). In the jewel case, the burned surface is suspended from the inside panel, so nothing comes in contact with it.
I'd suspect the surface may have gotten scratched or picked up some debris or maybe even oils and such on the surface. Double check that surface again to see whether anything happened to it.
Judging from your 2nd scan, esp. check the outer 1/4 edge of the disk. Your 2 scans look almost the same ... except from the 3.25 GB mark. Something happened to the last 1.2 GB of area on that disc.
Also, check your computer case and immediate surrounding area for debris. I once had a tiny chunk of a peanut drop into the burner tray, and it gave me a big time scare - ie. a rescan of a disc looked horrific compared to the original. Particles, dust, oils, fingerprints, etc ... all can factor into the scan results.
BTW, for those who couldn't find his scans right away:
His 1st Scan
His 2nd Scan
The suggestions for updating firmware would be a good idea. I think you can do much better than 77,090 PIE total burning at 8x on YUDEN000 T02's. The PIF total of 359 may be reasonable for your particular batch, but I'd like to see that PIE total drop to <20,000 if possible.
Good luck. Let us know how it turns out.