Crichton has this habit of writing horrible endings. It's like he decides he's written enough, so slaps on this ridiculous "and then a bunch of magic happens to clean up this mess that I've written" ending on there and sends it to the publisher.
Deus Ex Machina, baby. The writer's block-having author's best friend.
"I wrote my main character into an unsolvable situation, but don't want to kill him off? Umm...well...ok, aliens from the future that haven't yet been even hinted at in the previous 500 pages come down, vaporize the evil corporate bad guys, restore the ozone layer, and give the protagonist's daughter a pony."
Crichton is entertaining, but it's fluff literature...candy for your brian. I try to balance out my reading; if I go for something like Congo, I'll break out The Complete Works of Shakespeare or Atlas Shrugged afterwards to make up for it.