I checked the scorecards of guan’s group.
on 16, crenshaw took a double bogey, mansero a bogey and guan a par. The slow play penalty was assessed on 17.
guan’s card has 3 bogeys and 15 pars.
I am guessing guan’s group is more responsible for slow play than guan himself.
A writer for Golf World tweeted that Guan was given three wanrings before the penalty. Also said that two other players were also given penalties for slow play today.