Honda Repair: Oil Change, temperature gauge, honda dealer

Question
I usually take my 03 accord to wal mart to get an oil change, because they are the only place that uses fram filters other than the Honda dealer which would use a Honda filter.  I suspect that the technicians did not change my oil because the temperature gauge is in the medium range, and I would suspect that new oil would be cooler. Is there any way to determine if they actually changed the old oil or put in new oil? Thanks  

Answer
Eric,
Your temp would not have shown any difference for just an oil change. There is way too much heat built up for 5 qts to make a difference. Just check your dipstick, if the oil on it when you pull it out is clean, not brownish, it more than likely was changed.
Dan