I will say that I don't know anything at all about this other than the video I found...but this is definitely an SKS, and Definitely NOT a slamfire. I say this because he drains the mag in two seperate bursts.
EDIT: here's another, completely unrelated one that also definitely isn't a slamfire.
The OP's question was:
Will lightening the trigger pull end up in your SKS going FA?
Now if the question was:
Can you do things that will make your SKS go FA?
The answer is, Yes you can,
although it will not be legal or safe.
The guys in the vid emptied the mag with 2 trigger pulls,
but that doesn't mean that their rifles were not slam firing.
The SKS has no internal timing mechanism or rotary locking bolt as an AK or other rifles do.
So they were simply disabling the catching mechanism of the hammer.
Which means, with no timing involved, the hammer can fall anytime it wants,
if the bolt is in full battery or not, this condition is known as "Slam Firing",
which in a worse case scenario can end up being out of sync to the point of having an "out of battery" event.