I remember watching the game with my Dad when Cosell reported the shooting. It was an emotional Cosell, a call that was chilling to me yet appropriate and not over the top, as Cosell could sometimes be. It was and is a piece of history, a rarity when sports (MNF) intertwines with the larger culture.
Not many years earlier, Cosell had a radio afternoon spot on ABC and it was one of the few places to get 10 minutes, if that, of sports in the early to mid 70s, the ESPN and blog (opinion, and heavy opinion w Howard) of its day. It was fitting he made the Lennon call in that Cosell was not afraid to discuss the social and cultural issues as they related to sports--his opinions on Muhammad Ali stick out as one example.
Interesting question 91 raises regarding "what if" with the Beatles, Lennon etc. Chris Hillman of the Byrds in an interview not too long ago said he thought the Beatles were their musical best between 1965 and 1967. One man's opinion, but he may have a point. The Beach Boy's Pet Sounds came out in '66 and is considered by some as the greatest album of all time and a huge influence on the Beatles.