When Ward is talking to Beaver while reading the "Mountain Sports and Fishing" magazine his hands alternate back and forth from holding the magazine up to resting it on his lap.
When Beaver visits the Firehouse, a piece of stock film footage of the Fire Department sign is shown that is severely scratched.
Miss Canfield has another student take the completed test papers to the office. Due to the sensitivity of test data, a teacher would do this himself/herself.
When Beaver is lying on the bed blowing up balloons, a clear reflection of the TV lights is visible in the balloons.