So far I know that doing a mission in full stealth and the expert driver asset prevent escapes completely.
Added Inside Man Assets on almost all levels so that you can buy a EXPERT DRIVER that 100% takes away the Escape. — source
What else affects escapes? Does difficulty have a part in this? Is it ever guaranteed to get an escape?
Best Answer
While there are currently no exact numbers on what causes an escape missions, I've noticed the following by observing when we get escape missions after completing the main segment of the mission:
Ultimately, escape missions are there to prevent the "quick and dirty grind" - if you want to go in loud and don't prepare properly, expect an escape to happen.