Is Southwest padding Schedules for OTP?

UPNAWAY

Veteran
Aug 17, 2005
2,192
685
DALLAS
Looking at April's D0 and A14 stats, I noticed the following deference between the D0 and the A14.
AA +12%, DL +16%, UA +17% SW + 25%

So it would appear that Southwest is adding some serious cushion to their schedules. Are there other factors that could account for this that I am missing?
 
This would not show turn times. This would only show the flight times. They are gaining 25 point in A14 after taking off.