Improper Triaging

Hi there,
I suppose this is a little bit of a venting session on my part but also something that I wish to learn from. I have only been working in emerg for 1 year and have been loving every moment of if. With that being said I did encounter a less the desirable situation last week. I was working in our ambularoty care area last night, where waiting time was approx 3 hrs between triage time and actually seeing a physician, which isn't that bad for our department.
Anyways....earlier that night I noticed a 5 yr old triaged with a presenting complaint of SOB, c-task 5...I kind of brought it to the attention of some of my coworkers but they told me not to worry that this pt had a long wait because of where they were triaged to, the complaint wasn't severe at all. 3 hrs later bring the pt into ambulatory area and they are in moderate respiratory distress, using accessory muscles, lower SaO2 for a child....Definately got the dr in there very quickly....

That certainly lessoned my faith in triage at times.... Any input on how this situation can be avoided in the future would be greatly appreciated.....