TF2: The Medic will be credited for an assist if he heals a Spy that successfully saps a building.

The answer is true because in the game Team Fortress 2, when the Medic heals a Spy who successfully saps a building, the Medic is credited with an assist. This is because the Medic's healing support played a significant role in enabling the Spy to carry out a successful sabotage on the enemy's building. The Medic's healing helps the Spy stay alive and continue their covert operation, making them an instrumental part of the overall effort and deserving of an assist credit.