Does the Specialist's Threat Assessment granted on a Sharpshooter trigger their pistol or Sniper overwatch shot?

The title essentially covers the main question.

A Sharpshooter requires 2 moves to use overwatch with their sniper rifle, and only one to overwatch with the pistol. If a specialist uses threat assessment on a sharpshooter that has used all of their turns, which weapon would be used if an enemy moves into their line of sight?

Additionally, if it is the sniper rifle, would it still trigger with squad sight?

After testing, it seems that a sharpshooter with covering fire only uses their pistol in a reaction shot, which isn't triggered with squadsight.

Besides that it works the same as any other normal weapon that other units use, (i.e. using covering fire it is a full reaction shot) with the exception that the pistol does not require reloading.