No Paul, they didn't have a drill - it was scheduled for the next day not they day the boarded. They have 24 hours to have a drill.
When you say everyone should have been able to get off alive, you're right. But that does not take into account human nature. People panic - all the time. Not having been given any instructions on what they should do they did what they wanted to do - ran - jumped - screamed - everything imaginable.
It's the nature of the human beast. I am willing to bet (sadly) that there would be panic on any ship should this type of event happen again. People panic, parents want their children with them, doesn't matter what they've been told - they are going to hunt them down.
You must always take into account human nature.