Only version of this story I believe is Tragedy Khadafi's story
1) He is from QB
2) Him and Nas do not get along and there is no point in defending him
3) Everyone else who told the story i.e. from Death Row have told differing versions of the story, coincidently so it looks as if they didn't get punked.
Either way QB runs you ninjas, ask Russell Simmons
Plenty of reasons for Trag to defend Nas, although I won't get into most. For starters, it was on a QB documentary at a time when amends had been made with Nas. If you asked Tragedy that same question regarding what happened 10 years ago, he would've told you that Nas' crew basically rallied anyone and everyone who was willing to ride with them to go see Pac, using age old methods like bribery. In fact, that was the night someone's car got hit with a molotov cocktail. Why? Because a lot of QB dudes hated/were jealous of Nas. I think Nas kinda owned up to it in a song years later although he never really gave any background.
So QB dudes were reluctant to ride with Nas against Pac. A Nas who had really been feeling himself, distancing himself from certain people and acting too good for the hood (in their opinion) and now all of a sudden he needed their help. Against a Pac who had rolled through QB before and a Pac most of whom respected. Especially Tragedy, who would go on to change his name to Tragedy KHADAFI (ahem), rename one of his up and coming rappers from Headrush to Headrush NAPOLEON and basically bit Pac's "Bleed through similar veins" steez for Bloodtype. And bit him again countless other times, including re-naming his 98 album Against All Odds. So not everything is so cut and dry.
As far as what happened between Pac and Nas when they came face to face? Only they know but one things for sure, both had a lot of respect for each other before and after that meeting.