Deliberate mistake: On the Hawkeye's radar screen, the Bandits virtually stand still after switching course to defend target (after destruction of the enemies' runway). While the Daggers complete their way to the Uranium plant, destroy it, evade the SAMs and return (save for Maverick, who got shot down), the bandits are still in the same place. This is a deliberate error: If the Bandits had progressed with normal speed, the Daggers couldn't have possibly avoided a confrontation on their way back. (01:34:42 - 01:40:30)
Continuity mistake: When Maverick calls Comanche, the sun is behind the Daggers. When they descend below radar a few seconds later, the sun is ahead of them. (01:31:16)
Suggested correction: The idea was to use the tomahawks to take out the airfield and prevent enemy planes from taking off. The SAMs could be evaded by flying through the canyon so the airfield was considered a higher priority target.
lionhead
While that may be so, those planes exit would have a difficult time out running and avoiding that many SAMs. It's not like the ship wouldn't have enough tomahawks to take out the SAMs as well.
Taking out the airfield was deemed necessary to complete the mission, taking out SAMs beyond the canyon was not. The original plan didn't take into account the pilots surviving the mission in the first place, so the Navy didn't bother with extra strikes on SAM sites. Maverick had to struggle to get them to approve this plan in the first place too, so he wouldn't be able to convince them to put even more effort into it.
lionhead
They still have to avoid the SAMs on the way out, no canyon to protect them then.