As Muay Thai promotions in Thailand tap into the hyper-violence visuals of MMA, modifying their rules and scoring trying to capture the MMA casual audience, promoting viscous knockouts and knockout rates with size mismatches & much sought bonuses, its Old School "don't hunt the knockout" ethos of its Golden Age and beyond has seeped into the UFC. Here Khalil Rountree who has trained a great deal in Thailand and expressed a great deal of respect for the art does a mercy finish (he's been known to not show restraint in the past), satisfied with a symbolic show of dominance. As has often been pointed out, Thailand's Muay Thai has been about dominance, not aggression. The dramatically raised slow fist here even somewhat invokes the executioner's strike that can be found in some traditional pre-fight Ram Muay.
He then, post-victory, performed a modified Wai Kru (respect to his teachers), showing how intentful his performance was. The wai kru was nearly removed from some entertainment promotions in Thailand. It's a beautiful thing to see MMA in some way kind of "catch up" to Thailand's Old School respectful fighting and dignity, while Muay Thai is busy trying to catch up to MMA.
via Sean Madden
There has been quiet, growing concern over the new damage seeking forms of Muay Thai. Everyone loves the bonuses and the pay, but not only is the long term care and concern for the fighters an issue, older generations worry about Thailand's Muay Thai losing its ethos, its way of being, as it seeks more eyeballs across the globe.
It's no small thing for Rountree to end a fight like this, in a display of values. It shows that Thailand's Muay Thai, as it traditionally has been, has something to say to contemporary combat sports beside what cool elbows, kicks or trips one can do. It's a centuries old sport of great violence, but its culture traditionally has carried with it principles of restraint and control, principles exemplified in its scoring (which Westerners sometimes have a hard time understanding), making its deeper value its greatest gift to the fight world. There is of course much to socially criticize in Thailand's Muay Thai as it has historically developed, the conditions and liberties of fighters, their economic well being, disparities and injustices of many kinds, but part of that history was also used to find and fashion a sport founded on restraint in the face of violence.