If you organize such events, you've got to strike a balance between letting the event too loose and risking that people lose interest, or controlling it too much and appear to be running a puppet show.
Basically, it depends on the story behind it all.
Say for example you have a murder mystery. Lack of clues might not be so bad as some players may be able to pick up the story and help out with ingenious ways, traps and so on.
But when you have a treasure hunt and people lose the clues once or twice or have to wait too long, the fun factor flies out the window.