PEI, my comment about the 15% being just enough was with tongue in cheek.
Mustangsally, the 737 didn't encounter wet conditions until partway down the runway. Touchdown technique would not have made any difference.
Tee Emm, I had the same thought. Easy to say with hindsight of course, but I'm sure the crew have had a good think about a few of the aspects of the incident.