Matthews' out was an early submission over a slow-starting Li.
It wasn't Matthews having decided, 3 months after a fight where he got absolutely outworked and robbed Velickovic (Fringe UFC talent), and lost a decision to Holbrook (Lel.) that he'd go from being a mid-sized WW with shit striking to being a huge WW and out brawling Jingliang on a complete inversion of what we'd seen from Jake to that point. The book had more-or-less been written on Jake Matthews, 4 years and 8 fights into his UFC career, as a good top-control grappler with serious heart/front running issues and mediocre stand up. What we saw out of Matthews in that fight was him surprisingly, 3 months after his last fight, overcoming the clear flaws that'd plagued him throughout his career.
The Matthews I know would have given up and gotten TKO'd in the second. I see Matthews-Li as being an aberration on the same level as if Ortega had wrestlefucked Edgar to a 30-27.