"Maybe a dumb question, but if 137 kts was the VREF, doesn't that mean that the stall speed may have been 111 kts?s?"
A reasonable question, and nobody answered, so I'll have a go.
I'm super lazy, so going from memory, last I looked was probably over 25 years ago, VREF was 1.3 Vs so stall with VREF = 137 would be 137/1.3 which is 105. I stand ready to be corrected.
Sounds right...
Plus - once below 200 feet AGL (with the ~200-ft wingspan of the 777) there would have been a growing cushion (literally and figuratively) from ground effect, allowing the aircraft to mush along at - or even slightly below - Vso.
Not that I'd ever want to have to count on it to make the runway.