In this episode Barney claims he has never taken a bad picture. Though in S5E04 "The sexless innkeeper' in Marshall's photo montage of their double date every picture of Barney is bad.
In Marshall's flashbacks of helping Ted's exes after the break-ups; He is seen consoling Natalie on their couch. This would not have happened after either of their breakups as the first was over the phone, and the second was in a restaurant. Unless Ted is hiding a third relationship, this could not have happened.
Right before Lily's camera takes the group picture while scolding Ted, Barney is shown holding his champagne glass in his left hand and about to adjust his tie with his right hand, but when the picture is shown after the flash, his right hand is holding the champagne glass, and his left hand is on his tie.
Marshall can't have a normal photo taken, but in the opening theme Marshall has several "normal" photos, especially at the end in the group photo.
Lily helps greet Amanda at the door and mentions that it's her birthday cake being made by Amanda. However when asked during the game just moments later about Lily, Amanda mistakenly guesses that Robin is Lily. Despite knowing that she is there to make a cake for Lily and actually just spoke with her a little earlier. Even for someone as stupid as Amanda (guessing a favorite color is "elbow"), this makes little sense.