When Dr. Max Bergmann meets Jeff Morrison, Max implies that he knows Morrison.
Of course Masi Oka and 'Greg Grunberg' have met before, in Heroes (2006). In addition, when Max tries to remember where he met Jeff before, Max screws his eyes tightly shut, which is the same thing Hiro did whenever he wanted to freeze time or teleport.
They got Liam Millers name from his picture facial rec through NCIC (National Crime Information Center). But he has no criminal record so he would not be in the NCIC data base.
Danny Williams is fan of the movie Enemy Mine (1985), starred by Dennis Quaid and Louis Gossett Jr. In Lele pu na manu like (2018), Lou Grover's family reunites for Thanksgiving Day. Lou's father is played by Louis Gossett Jr.