I support the decision you made with your progress-tracking, but i would be a grade harsher and disqualify them if they decide to skip the boss again next ID. I would even do it now, because the general opinion on this seemed to be clear before they skipped DG. Aaand maybe even a step farther, DQing them from S&V for the sake of farming gear and their arrogant attitude toward all the other guilds here.
It isn't simply just this one occurence of boss-skipping, but this is the time we have to decide how to handle it in later progression. When S&V NiM launches, should we skip Thrasher (which was the first harder boss there we encountered) immediatly just to have a chance for the first-kill ofsubsequent bosses?! Maybe even rush for the end-boss to claim First-kill Styrak?!
The rules have to be clear for the next time. Sure, anyone can make their own progression, allowing to skip (or vice versa, if the decision in this thread come to the conslusion that boss skipping should be allowed during the next progress).