When they arrive at the ice rink, you can see the logo of the Scranton/Wilkes-Barre Penguins, which are the American Hockey League affiliate of the NHL's Pittsburgh Penguins.
The picture Michael misidentifies as Luke Perry is actually of James Dean.
According to Michael Scott, his birthday is March 15th, the same as Eva Longoria.
When Michael hears that the test result of Kevin is negative, he reacts like he's devastated, because he thinks 'negative' is bad. Same thing happens to George Costanza from Seinfeld (1989), in the episode 'The Pilot'.
The gift that Pamela gave to Michael on behalf of the office staff is Night Swept, a fictitious brand of cologne. In Season 1 Episode 6 "Hot Girl", Michael had been using Night Swept as an substitute to the famous Drakkar Noir cologne.