Okay Newfie, I'll try to help you with this one (damned newbies ).

What usually causes a cigar to split is when the filler and binder are more moist than the wrapper. This would usually occur if the cigar was a a higher humidity before being moved to a less humid enviornment and smoked prior to the entire stick having time to reach the same lower humidity, although there are exceptions to this.

I suspect that your Punch was exposed to very dry air between the time that you took it out of your humidor and when you got ready to smoke it after your golf game. Was it a dry day? Did you have the cigar in a tube of a humidified cigar wallet while you were golfing? I would guess, not.