The issue is terrain more than a fleeing enemy.
On the Russian steppes, with good air reconnaissance and communications, portions of fleeing Russian units could escape in the confusion, though often as not, they were overrun.
In this situation, three combat support units, an anti-tank battalion, a mortar battalion, and an artillery battalion, retreated off of the jungle track. The enemy followed - but not just any enemy, the tanks and motorized units.
In real life, these elements would have had to laboriously hack their way through the jungle with significant engineer support, making their own road as they went.
That's the issue, not the overrun.
Then, to add insult to realism injury, it happened again, with the Allied mobile units passing through a second hex of jungle, moving in two days what in game time would have likely took 45 days or so at 2 miles a day.
Know the enemy and yourself...