Corrected entry: During the episode, it goes back to 1968 and in the closing credits Eric is listed as being 7. However, he can't be because in 'Eric's Birthday' it was 1976 and he had turned 17. Thus in '68 he would have had to be 8 or 9 (depending on his birth) but certainly not 7.
Corrected entry: In the beginning of the episode where Bob and Red are competing with their Veteran's Day barbeques, Red is seen wearing the uniform of a Chief Boatswains Mate (BMC). However in a later episode where Kitty and Red are trying to remember how they met, in a flashback, Red is seen wearing the uniform of a Machinist Mate 2nd Class (MM2). Surely he advanced in rank, but I doubt he changed rates (jobs).
Corrected entry: After the parade, Red shows up in his Navy uniform. He has several medals on the shirt (three, I believe). The only problem is that one of them is an Army Commendation Medal. Red was in the Navy. While different branches of services can recommend medals for other branches, had the Army recommended Red for a medal, the Navy would have given him a Navy Commendation Medal, not the Army equivalent. The Army medal has the several small stripes in the center (as the one Red is wearing does). The Navy medal has no pinstripes only the two wide ones.
Corrected entry: The actors playing Eric, Hyde and Kelso at a younger age are all credited as playing them at the age of 7 and 13 but we found out earlier in "Halloween"(episode 30) that Kelso is actually a year older than them so the actors playing him at the age of 7 and 13 should have been credited as playing him at the age of 8 and 14.