Any of several things could either require landing rather than continuing to the destination. Some others could make it advisable.
From the looks of the WX here in NC, it doesn't look like WX radar problems unless the WX is worse west of the mountains. Likewise for engine/wing anti-ice systems.
One IRS failure could result in loss of one of the two sets of flight instruments (Capt or F/O) which could make a landing advisable.
Pressurization, hydraulist, etc, could cause a diversion. The list would go on to loss of 1 engine at the worst end.
OK, looks like the plane was only on the ground in BNA a little over an hour, so that leaves out the more serious problems. Heck, getting contract maintenance to show up could take that long, so it looks like something relatively minor.
Of course, there's always the possiblity that the remark in the computer is wrong and that a passenger had a medical problem or something.
Jim
