During the flashback scene when Marshall and Lily are listening to Ted on the radio the popcorn by the radio appears and disappears.
During Robin's "Going-Away Party", Robin's hair changes from over her ear to behind her ear between shots.
Robin is a reporter for Channel 22 in Red Deer, AB; but Red Deer does not have a News Station 22, only Channels 4, 8, and 10.
In her broadcast journalism reel, Robin is a reporter in Red Deer, Alberta, Canada. She is reporting on an ice fishing competition in Lake Athabasca, but Lake Athabasca is nowhere near Red Deer; Lake Athabasca isn't even accessible by road, but it's about a 6 and a half hour drive from Red Deer to the closest drivable settlement, the hamlet of Fort McKay, and a further 100 miles (approximately) to Lake Athabasca. It's very unlikely that she would be reporting on an ice-fishing competition so far away, when there are much closer rivers such as the Peace River, South Saskatchewan River, Athabasca River, and, of course, the Red Deer River, to host such a competition.
Marshall's resume identifies himself as the 1995 Nicollet County Dunk Champion. Marshall is from Saint Cloud, Minnesota, which is located in Stearns County. Nicollet County is in southern Minnesota (St. Peter).