Penalize is not the solution... beacuse some times you really lost connection or even WGT can crash or kick you out with no reason.... yeah, yeah clear cache and all the stufff!!! lol
What WGT should do is:
give the remaining players all the XP they deserve... For example if the quitter last up to #5: give the survivors of such round the XP of that rounds UP to hole #5... is very disapointed to see a player leaving the game when there is only 1 hole left... you will lose all those precious XP... and if luck is not on your side... the disconection may froze your game as well and you will no longer be able to come back to take at least your own XP you earned.
As far As I know there is a button that says "end round/main menu" if that button exist, everyone can use it as they please... but wgt need to take care of the ones who stayed to the end.
Another solution can be... to earn every XP after each hole.... and the "end of game message" would be just a summary of what we already earned... this way I would not care If I finished playing the round "solo" If I still get my XP and of course if the game don't get froze because of the player that quit!
but... just some thoughts!
Jvr