Many people who wonder why Sasuke got so much leeway in the final war forget that Sasuke wasn't alone.
Sasuke was also accompanied by Orochimaru, who held all four Hokage hostage and vowed to assist Sasuke.
Oro flat-out said that he would destroy Konoha if Sasuke wasn't happy with their answers.
Tobirama, of course, wasn't happy and decided he'd stop it.
Only to be reminded that he was a reanimation, and therefore Oro had complete hold over him.
Truth is, Hashirama couldn't have stopped it either. Oro could've either put a mind-control kunai on his head or sent Hashirama back to the afterlife and focused on the remaining three with even more concentrated power.
It is a hilarious and ironic inversion of the situation: Tobirama one day opposed Madara because he was confident Hashirama would back him up (which he did). But now he realized that if he badmouthed Sasuke, Hashi (who is also a hostage like him) would be unable to save Konoha this time—Sasuke's threat to destroy Konoha, unlike Madara, was backed by an even stronger person than any of them: Orochimaru.
Even Hashirama acknowledged it:
So yes, contrary to what many people think, they'd not be able to stop Sasuke if he got pissed off at their reminisces about the Uchiha, and that's why Tobirama needed to restrain his mouth, Minato needed to stop defending Hiruzen, and Hashirama needed to make a stand against his brother's foul mouth that he failed to make when it came to Madara many decades ago.
Now, when the final war ended and Sasuke decided to kill the five kage instead of Konoha's civilians, he again would've been backed by Oro.
And let's remember, with Guy crippled, Nagato, Obito, and Madara dead, and all the Hokage back to the afterlife, Sasuke was the strongest human alive on the planet, with Naruto being his only equal. Add Orochimaru, and the power difference would be too much even for Naruto, never mind the five kage—Orochimaru is now effectively immortal, has mastered every sealing jutsu, has a much stronger body, and most importantly, he already showed a multi-kage-level feat by restraining three Hokage.
Sasuke only changed his plan because Naruto convinced and empathized with him. If he didn't, Sasuke would've just wrecked havoc on the five kage without further question. The raikage, Gaara, Mei, Tsunade, and Onoki won't stand a chance at this point, and even if Naruto defeated Sasuke, he'd not be able to save the five.
This is why Sasuke was ultimately "pardoned," not because everyone was too forgiving, but because Sasuke was too dangerous to oppose at this point. And a huge reason behind that danger was Orochimaru himself. Even Naruto, once promising a better way to Sasuke, could not take his words back and vouch against Sasuke in any trial.
Note another irony: while Orochimaru was the one to destroy Konoha once, he was also the one to finally save it from Sasuke's wrath—by threatening the Hokage and holding them hostage.
