I can't tell if Liquid is falling off or NRG is just this good.
NRG is a really good team tbf.
But the real answer to your question is Liquid are ass.
Liquid surprised me and came back. I know they have a tendency to lose the 1st map and rebound the other two but it seemed really telling of NRG's potential. I still think that NRG needs to replace Fugly, and if it was a dream pick: bntet.
On top of that tendency, they played one of the best team on Overpass. Despite the rather one-sided scoreline, it was expected from pretty everyone that NRG would take this map, especially after the strong come-back they made on the first side. The worrying factor for me was Inferno where Liquid was clearly favourite and still struggled to take the victory, which to me is a clear indication of their current weak form. NRG can have lots of regrets not being able to close it 2-0 but that's also why Liquid is still a Top3 team (and not 'ass' as Mr Britcunt so nicely put it out). You can't just let them underperform, you also have to play at your best on eventually all three maps.
Either way, this is clearly Liquid's tournament to lose but I am not too worried. NRG is clearly the biggest threat in the whole tournament. If BIG wakes up and trash Gambit (which I expect them to do), then this could get interesting, but anything but a win would be clear underperformance from Liquid and they are not at a state where they can allow themselves to throw T2 tournaments.
Wasn't worried, not even a second.