When ghouls attack! (and players do nothing?)

Something very interesting happened in our last Pathfinder session. Only 3 players showed up and carefully finished clearing out pretty much the rest of the first dungeon level that they had been working on. The only thing left was the earth elemental that had previously wiped out most of the party. So this time they approached with a plan and were prepared to fight it carefully. They went back to town to rest and make final preparations.

On their way back to fight the elemental they encountered 3 ghouls in the graveyard above the dungeon. They saw them a long way off and were not surprised. They did . . . nothing? To be fair the ranger attacked them with arrows, but the two spellcasters basically passed. These are 3rd and 4th level Pathfinder characters so the ghouls really should not have been a serious threat.

But here is basically what happened:

[I am leaving out the fiddly 3e maneuvering around crap, this is the essence of the fight]
 
Ranger shoots and kills a ghoul.
Remaining ghouls charge and paralyze the ranger.
Witch and summoner frantically begin casting summoning spells.
Ghouls kill the ranger.
Summoned monsters kill the ghouls.

Whoops.

If the spellcasters had taken their second round actions in the first round of combat the Ranger would have lived. Is this sort of thing common in other people's experience?