The sentry cannons shooting at nothing was a reference to Aliens (1986). In the original cut, the cannons are shown as firing with no significant effect; in the director's cut, there was an additional scene that also served little to no purpose.
Archer mentions Eddie Waitkus, who played major league baseball for 11 seasons with the Chicago Cubs, Philadelphia Phillies, and the Baltimore Orioles. In 1949, Waitkus was shot by a deranged admirer. His story was the inspiration for The Natural (1984), starring Robert Redford.