Tygart didn't have much choice in the matter. When Floyd approached him and started spilling the crown jewels of USPS/Discovery cheating, what was he supposed to do? Should he have told Floyd to pound sand?
Blowing Floyd off would have been the American thing to do (if your standard is the United States Olympic Committee, that is), but Tygart chose to do the right thing and pursue an investigation.
To get people to talk, you have to trade for information. All the Posties traded (and got insanely good deals), except Lance. The main reason Lance didn't get any kind of deal was because Lance was still hiding behind all of his lies. Those lies persisted throughout the entire process--from presentation of charges, past Arbitration, and CAS Appeal (both of which Armstrong spurned).
Should Lance have gotten a sweet deal--even though he remained a massive liar? I don't see why. He was a central hub in a (for cycling) huge doping conspiracy. He utterly deserved a lifetime ban.
Lance fought USADA in 2 ways: (1) the stupid federal court case; and (2) his last ditch plea for help from his buddy McQuaid. Did those sleazy tactics entitle him to a deal? I don't think so.
Lance didn't fight USADA in the Arbitration. He might have been able to win on the SOL issue, but he didn't even try. What right does he have to say that the process was unfair when he didn't even participate? It's not like he couldn't afford to participate--at the time he was soaking up his cancer and endorsement money.
Lance's pitch today is that he deserves a deal even though he never told the truth to USADA and never participated in the antidoping process. The real question isn't whether or not Lance v3.0 (the whiny version) was harshly treated--the real question is whether or not cycling has a role for a dope distributing fraud and lying cheat. It doesn't look like a close question. Cycling, and all sport, is way better off without Lance, than with him. Anybody who trusts Lance to complete clean is an absolute moron.
In the world of Lance, the doping ringleader should get a deal that is roughly the same as the deal that his underlings get, because in the world of Lance, the ringleader is not one bit more responsible than his underlings. That might work, in the world of Lance, but it shouldn't work in the world of decent people.