Is the DF Penalty Quirky?

Twice I've seen it happen now where I have a few friends in a party and we go on DF to fill the remaining slots for a duty. One of us goes afk for a sec and fails to hit commence duty within 45 seconds. A seemingly random party member gets hit with the 30 minute penalty, not even the person who failed to commence. Now, the person who gets the penalty hadn't dropped out of any other searches all day. Isn't the penalty supposed to hit after three drops in a day?

Am I not understanding this right for is something funky with the penalty? Has anyone else seen this?

If you are in a party, it adds to the withdrawal count for all of you.

It's likely that one of you has withdrawn twice before earlier in the day.