What are the consequences of a "doorway arrest" where police without an arrest warrant enter a person's home and arrest the person who opens the door?

"Doorway arrests"--where police without an arrest warrant knock on a door, then arrest the person who opens it--have been the subject of numerous cases, with widely differing results partly attributable to their particular facts. (See United States v. McCraw (4th Cir.1990) 920 F.2d 224, 228-230 and 229-230, fn. 5 [warrantless arrest inside hotel room unconstitutional where defendant opened door halfway in response to officers' knock, then tried to shut it], and cases cited; State v. Morse (1984) 125 N.H. 403, 480 A.2d 183, 185-187, and cases cited.) There are several unique factual wrinkles here, such as it was Munford's girlfriend, not Munford himself, who opened the door. ⁶