Yes, let me give a breakdown of what happens.
I click on an action area in a room with char_X, the action goes
show_message to char_X
add item_1 to char_Y
I then switch to char_Y and check it's inventory, but it's empty. I bound F2 to the following action:
add item_2 to char_Y
When I press F2, item_1 and item_2 both appear in char_Y's inventory. This happens even if I press F2 while still controlling char_X