That's more of a display of the Rubi's healing abilities than it is Salvador being exceptionally awesome.
Salvador is no doubt overpowered, but when you're using half blue items you can't really call a "white weapons" run through legitimate.
Sal is capable of using it to heal while also putting out insane damage from the other gun. Since the Rubi/Grog should never have been used for damage output in the first place.
But he is using it for damage, it's the only thing he's got that's giving him slag, which while not direct damage output, is tripling the damage the other gun does. Sure, any slag gun can do this, but it's also giving him the benefit of healing at the same time.
The only thing keeping him alive is the healing it provides. Sure he can wield it at the same time as the other gun, but any class could do this with a Rubi, it'd just take longer with all the weapon switching.
Again, when I read a title that implies "white weapon run through" for a video that is supposed to showcase how a character is overpowered and then they use the passive abilities of some red-text blues to be the workhorse for keeping him alive, it shows me that the blue items are giving him more than anything else in his build.
Currently playing: UnEpic (PC), Dragon's Dogma DA (360), Borderlands 2 (360)