Detailed photographic analysis of the last two cometary flybys didn't show any ice geysers, or even geyser vents.
Then, their lander didn't work because it was designed to spear into slushy ice, not solid rock, which is what they found.
Watching the televised post-mission conference, you could see how shaken the mission scientists were. Their models had failed to predict pretty much everything they'd observed.
Yup