0.8 is not flawed. The flaw lied in 0.7 and below. If an upgrade was hastened, the problem would not have been a problem at all.
Sadly, 0.8 is flawed its "one job" was to faithfully follow the behavior of 0.7, "bugs" and all. It did not. Had we known about this behavior in 0.7 or had testing turned it up we would have made sure 0.8 behaved the same way.
This is the nature of a distributed consensus system. The primary definition of right and wrong is "consistent" and if you aren't consistent you aren't right, no matter what.
The testing should have happened with the older version of Bitcoin. I don't see how testing 0.8 would fix this issue, given that 0.8 fixes the bug.