Is this the LAX Airport Monitor they're talking about? Cool site!
That website is cool!
If you let that reconstruction run on http://www4.passur.com/lax.html a little bit longer, a weird thing happens at about 12:55. In that same spot where the "rocket" showed shooting up from 1200ft to 7200ft, a "General Aviation" track shows up and hovers there at about 2500ft for several seconds. Hmmm.