In the episode "First Time in New York", Barney remembers his first time and claims that his comforter stank of menthol cigarettes for weeks. However, in this episode, the younger Barney is shown having his first time in Rhonda's bed, not his.
James mentions a figure skater doing a perfect jump and messing up "on the arabesque." This is the incorrect term used in figure skating and should be called a spiral.
When Barney is leaving Rhonda towards the episodes end, there is a click sound of a door unlatching as he pulls the door fully open. However, the other room is visible before Barney even motions to pull the door so the door is obviously partially open. Therefore, there should not be an unlatching sound effect.
Ronda the man-maker calls Barney's mother Patty while they were playing cards, but when we meet her in the future she is actually called Loretta.