It is always important to read the .info.
Fair enough. Let's try again.
1. Install and test run OSS.
2. Install and test run Opera.
3. Verify that the folder /usr/local/lib/opera/plugins exists. It does not, even though it is present in the opera.tcz package.
4. Install and run getFlash10. The wget operation completes.
5. Verify that libflashplayer.so has been installed in the Opera plugins folder. It has not. Because the getflash10 script could not find the missing folder, it assumed that Opera was not even installed.
6. Run Opera and go to Youtube. Opera complains that Flash is not installed. Of course.
7. Check the contents of the new flash10.tce extension. All it contains is libflashsupport.so. (Hmm. The getflash10 .info claims that this should be a tcz package. No matter.)
8. Manually create the missing plugins folder.
9. Run getFlash10 again.
10. Check for libflashplayer.so. Now it has been installed.
11. Run Opera. Now Flash works.
12. Check flash10.tce. Now it contains libflashplayer.so.
13. Reboot and check Opera. Flash still works because the flash10.tce extension provides the missing folder when it is installed.
14. Make a dummy extension that contains an empty folder.
15. Install it and check for the empty folder. It is missing.
If this is still a case of RTFM, I apologize. But it sure looks like a bug to me.