While Wayne is examining the phone records, his pager begins buzzing. He places it on the desk and ignores it as it continues to buzz. The shot cuts to Amelia listening to the phone ring as she tries to page Wayne.
That is not the way that pagers worked. Instead of listening to the rings, Amelia would have called the pager number, entered her phone number when the system answered, and then would have hung up and waited for Wayne to call her back. The shot should have cut to her holding / looking at the phone receiver waiting for the call.
A key plot point is that Harris James has a chip in his beeper that emits a GPS signal, pointing to that he could be found if that was desired. However, hand-held GPS devices were only first available in 1989, while the 'Selective Availability' order of the US Defense Department, which lasts until 2000, decreases accuracy of positioning data received by satellites, which is only when such a thing as a 'GPS transmitting chip' could be feasibly sold to private companies.