During the hot tub scene, Barney takes a drink from the liquor bottle. Mandy Moore's character then reaches for the bottle and the cap is back on the bottle.
Whilst looking for some 'ointment', Ted picks up a bottle of massage lotion which the others admit was from Gael's massages. In all of the scenes showing them receiving a massage, they were all fully clothed. Massage oil isn't needed unless there's bare skin, it would just make their clothes very oily if used whilst dressed.
In the episode, when they are in the hot tub Barney (Neil Patrick Harris) is seeing drinking alcohol from an open bottle. However, when he passes the alcohol bottle to Amy (Mandy Moore) it is sealed.