I've notice them close rather quickly too. I don't know if the timer started before or after, but I've had multiple reports that were cleared come up, and before I'm able to see that it was cleared the alert is gone. It would be nice to have a user set countdown, so if I want it to stay a few extra seconds I can.

I also think some users may be confused as to when the location of a report is set. I think some users MAY be hitting report as soon as they see something (which sets the location in Waze) and then hitting submit as they pass the incident. So therefore the countdown starts too early for other users.

Every now and then I see a single report that is "too early" and this is the only explanation that comes to mind (besides a client bug of course).