When can initiative like Rebekah's be helpful? Under what conditoins can it lead to trouble?

I would say that an initiative like Rebekah's would be helpful when there is some kind of emergency, whether it be someone in need of some major medical assistance, or if there is a group project that needs to be complete within a matter of three or less days.  However, some people can be overly initiative.  They might like doing a lot of work, but it won't look good if a one  member of a group does not allow the other members of the group to contribute their ideas.