Flynn was a bad pick, especially after you just took another PG. That pick was protected btw, so it would still be Minnesota's.
Which means the pick was even lower really, and might have been a second rounder after all the protections (if I recall correctly). Which in actuality means the trade was essentially Jefferson and a late first for Garnett (the other four players were money or role players at best and everyone knew it).
Flynn wasn't the bad pick, Rubio was the bad pick. They should have gone Flynn and Curry with those two selections.
They messed up the rest of the team, drafted another PF who couldn't play defense, etc...
No bearing at all on the trade itself. Jefferson and a late first for Garnett.
Boston gave up a lot more than the Lakers, at the time. The fact that Jefferson blew out his knee and Marc Gasol made a massive leap to become NBA worthy shouldn't factor into your evaluation of the trade.
Gasol was coming to the NBA that season no matter what. Sure he got a lot more playing time in Memphis then he would have in L.A., but he was ready and coming and everyone knew it. Sure no one had any idea how good he would be, but everyone knew he had talent. Memphis insisted on him being included because they liked what they saw. Jefferson blowing out his knee obviously has no bearing on the trade at the time. And Jefferson even after it, is still better then Gasol, but he still hasn't developed any defense which could have been predicted.
If Melo blows out his knee Shaun Livingston style does the Knicks trade suddenly become a bad one? You can only go with the information you have at the time.
And the information at the time was Jefferson, a young promising PF who was injury prone, a late first round pick, returning a pick that might have turned into a second rounder anyway, and a bunch of role players for Garnett, vs. a young more unknown but promising center, a young promising PG, and 2 late first round picks for Gasol.
Everyone here was infatuated with Jefferson, who is still the best player involved in those trades (outside of KG and Pau), but the C's really didn't give up that much for Garnett when you really look at the trade.