After you destroy the generator, enemy randomly will spawn indefinitely and you must get out quick or you will be pinned.
I told my team to suppress ahead of me near the generator.
I jumped over the barricades that are closest to the field and ran alone up to the extraction point while my team stayed and kept the soldiers busy(they eventually die).
Enemies were continuing to spawn as well as a helicopter, but I was well ahead of them on the hillside already.
There are 4 enemies hiding out at the extraction point that are easily sniped by yourself.
I boarded the helicopter alone.