After using a quick ability it should return you to the last non-quick ability weapon slot that you were using. But if you use both quick abilites consecutively it instead returns you to the first quick ability used.
To reproduce:
With sawbones equip primary weapon, use the quick ability key to use your defibrillators, then use the other quick ability key to throw a medpack.
Expected result:
After using both quick abilities it returns you to your primary weapon.
Actual result:
After using both quick abilities it returns you to the defibrillators, the first of the two quick abilities used.