Are they right- or left-handed? Most carry the gun on the strong side of the body. What side of the body is the wrist watch on (if you can see it)? Right handers generally wear the watch on the opposite hand. This will tip you off on where to look. Is there a cell phone that you can see? What side are they wearing it on? If not on the strong side, then maybe there is a reason for the off-side carry? Possible indicator.
I really liked that seeing as how it describes me perfectly. The only reason my cell phone is on my weak (left) side is because the right side is reserved for a gun and holster.
I don't mind an article like this. CCW permit holders make up somewhere between 1-6% of the population in a shall-issue state and not everybody carries all that often. The people that actually do carry all, or most of, the time are incredibly rare. I'd rather have an officer with a bit of knowledge like this before his first stop of somebody with a CCW.