the challenge to the NFL is whether or not they knew about the impact of concussions and tried to cover it up. If the plaintiffs can prove the owners put the players at risk, and lied to them, they'll win the suits.
I seem to recall that, while Troy Aikman was still playing, one of the helmet companies was working on a new (for the time) lighter weight helmet. The thought was that as players tire, they don't keep their head's up like they should increasing the likely hood of getting concussed. I think the leagues has been onto the issue of concussions for a good while, but I don't think they or really anyone really realized how badly the long term as well as the short term affects truly were. I don't think they turned a blind eye to it though.
