Continuity mistake: When Lily and Marshall are discussing which band to book for their wedding, the way Lily's shirt hangs changes frequently between shots. Sometimes the shirt hangs straight, in other shots it is folded back on itself.
How I Met Your Mother (2005)
1 mistake in Best Prom Ever - chronological order
Starring: Jason Segel, Neil Patrick Harris, Cobie Smulders, Alyson Hannigan, Josh Radnor
Barney: It's gonna be legen...wait for it...dary!
More trivia for How I Met Your Mother
Question: Has the mother been cast yet? Also, does the film crew know who the mother is already?
Chosen answer: She was finally shown at the very end of the last episode of season 8, continuing into season 9. The actor's name is Cristin Milioti: http://www.imdb.com/name/nm2129662/.
Knever