"Umm, they probably weren't all the much different in age than the typical high school student."
They look older than high school students to me...but maybe I'm more observant than most. There WAS a substitute driver that day...interestingly enough they boarded on the sub's day.
"One of the guys was wearing shorts with a black trench coat."
Typical high school dress? In Florida? Shorts and a black trench coat typical? No, I don't agree. Surely after Columbine, at the very least, the black trench coat should have set off some alarm...
There are still a few "Goth" types running around. I saw a gal dressed that way last weekend at Chili's in Central Texas. No trench coat though. I was also in Florida last week and I can say it was pretty warm. But I don't think the Goth types let that stop them.
As far as the age difference, have you dropped by your local high school, especially in the lower socioeconomic areas, lately. You see lots of beards and partial beards. To my eye, the guy with the beard looks younger than the beardless one. I could see him as high school age, but the other one would be a bit of a stretch. Still, the driver likely wasn't paying all that much attention.