Revealing mistake: At the airport when Jack says 'tow it', there is an extra waiting for his mark to walk outside seen in the reflection of the doors.
Revealing mistake: At the part where the two are racing back to the house. At the very last light when the father turns left, you can see that the driver of the Mercedes is a stunt double.
Answer: Who says they had to have been legal adults to date when Top Gun was popular? They could very well have been teenagers and got engaged shortly afterwards. If Teri Polo and Owen Wilson are playing characters that were born the same years as the actors themselves they would have been 17 and 18 respectively when Top Gun was released. If they are playing characters a few years older than they actually are, which is entirely plausible, what Pam says makes perfect sense.
BaconIsMyBFF