THIS.
If the Warriors were truly all that great, they wouldn't have been down 3-1 to begin with thus facing multiple elimination games. Anybody that watched the series objectively should clearly see that the Thunder was in control and winning by playing their style of ball. However, they suddenly stopped doing the things that got them the 3-1 lead in the first place. OKC already had a reputation for falling into those kinds of traps so, no, it had little to do with anything the Warriors did. At all. The only credit I give to Golden State is that they were able to take advantage of the opportunity. Not every team can do that.
Lastly, calling GM6 anything but a choke just shows a lack of awareness. OKC outscored the Warriors in each QTR until the 4th when they were suddenly outscored by 15. At home. In a game that puts them into the Finals.
Before anybody points to Klay's hot shooting as the reason for it, I'll remind you that OKC only scored 18 points in that 4th QTR. The Warriors hot shooting wouldn't have mattered if OKC didn't pucker up and go into the tank offensively. That's precisely what they did. Some good defense by GSW, but largely poor shot selection, ISO ball and unforced turnovers.