When it comes right down to it, you're entirely at fault for what happened in your group because you should have read the LFM advertisement correctly.
"Experienced players" LFMs attract the very worst players because they assume that the other people in the group will be experienced and will be able to carry them through the quest.
If you really want experienced players, put "BYOH" in the LFM. You'll weed out all of the players who don't think that a Fighter, Ranger, Paladin, Rogue, Bard, Barbarian, Monk or fleshie arcane caster can be self sufficent in a quest. Eliminating the players who *need* a healbot stapled to their behind makes it possible to find a group that can take care of themselves and only uses a healer to go faster through a quest instead of sitting at the entrance, sucking their thumbs while they wait for their nanny to show up.