At the end of the episode Buckley makes a video call to the Epps family, he says that he and Don "under different circumstances, could've been friends" and they "could go skiing". In real life, Fisher Stevens (Buckley) is very good friends with actor Rob Morrow (Don), and the two regularly ski together.
Buckley asks how many Eppes guys are in the FBI and jokes about whether they've got an astronomer sending them satellite photos and Alan says "He's on sabbatical;" this could be a reference to Larry, who is not an astronomer, but is an astrophysicist.