Over at Vanity Fair, Scott Price has a long piece on “Diner”:

The second crisis hit when an on-set fire cost another night of shooting, and MGM refused to budget another day. Levinson needed more time. Sova suggested breaking out a second camera in the diner, to speed things up by filming actors on both sides of the table simultaneously. That, however, created a problem with sound: instead of clipping a lavalier microphone to just one actor and allowing him to say his lines cleanly—that is, without overlap from other actors, so it can be edited into a scene later—the new situation demanded that all the actors, on-camera and off, be miked. Robert Altman aside, at the time it was still rare to use overlapping dialogue, especially for trivial, tabletop chatter. “What Levinson did in a revolutionary way 30 years ago,” John Hamburg says, “is something we’re doing now.”

It was, for the final two weeks, a kind of liberation. “Because we didn’t have to worry about overlaps, we could really ad-lib,” Guttenberg says. “You could ad-lib offstage and throw the guy a fastball, and he could catch it and throw it high. That’s what made the experience so unique in filmmaking: you didn’t have to match ‘what we did last time.’ It was ‘Just give me something extraordinary. Take it wherever you want to go.’ ”

…Banter is a delicate thing, crippled by obvious effort, destroyed when, as so often happens on sitcoms, it’s reduced to point scoring or put-downs. Reiser was so quick, so on, that there are moments in Diner when he sounds as if he’s trying out material. But Levinson was also going for something deeper, a casualness implying dynamics and affections that reach back years, and even the screw-ups nail that quality. The best comes when Guttenberg’s Eddie asks Boogie, “Sinatra or Mathis?,” and Rourke brushes him back with “Presley.” “Elvis Presley?,” Guttenberg’s Eddie says. “You’re sick … ” He starts to improvise, but it’s like watching a kid let go of the handlebars for the first time: he knows he’s going to crash. “You’ve gone like two steps below … ,” Guttenberg stammers, “in my … my, uh, book.” Clearly, a blown take: The actors giggle, Stern spits up his drink, breaks character, and says, “Once again … ” But rather than splice in a cleaner run, Levinson went with the mess.

For more, check out this Q&A I found in an old issue of American Film: My Dinner with Barry (Robert Ward)

And yeah, that’s the same Robert Ward who wrote the famous “Straw that stirs the drink” Reggie profile for Sport.