Hello i made some research, so here is the result:
Correct me if I'm wrong
One single tap:
STD :: Fingers Status changed - Current Finger(s) 1, Last Finger(s) 0, Button Data 0 State 0, Touchmode 0, Touchtime 0, PacketsCount 0, FingOnBtn 0, PID -1, SID -1, RM 0, ESwipes 0, Drag 0, Tap 0
Double tap:
STD :: Fingers Status changed - Current Finger(s) 1, Last Finger(s) 0, Button Data 1 State 1, Touchmode 0, Touchtime 0, PacketsCount 0, FingOnBtn 0, PID -1, SID -1, RM 0, ESwipes 0, Drag 0, Tap 0
Difference between these two is Button Data and State.
If this is correct and double tap is Button Data 1 and State 1 then it show always when i do gesture (double tap), but sometimes it doesn't shows in OS X (explanation: Double tap to open folder, it always shows Button Data 1 and State 1, but sometimes it doesn't open it, same thing is safari double tap to highlight text)
I also made i video for this look carefully on time in terminal.
It happens twice on start and once 0:42 and 1:01.