"I wasn't that surprised," James Remar told Usmagazine.com at Sunday's Screen Actors Guild Awards. "It was nice."
See backstage photos from the SAG Awards.
Remar said the two were always "very comfortable together. They were very chatty from the day they met. They really seem to enjoy talking with each other.
"There was never any indication, as far as I can see, that it was romantic," he added, "but they just seemed to be friends instantly."
The cast has been celebrating their wedding at all the awards shows.
"They're all a little bit of a party," Remar said of the awards shows.
See what all the stars wore to the 2008 SAG Awards.
Hall and Carpenter walked the carpet for the first time as a couple at the Golden Globe awards earlier this year.
They eloped in California on New Year's Eve .
See photos of more stars who have eloped.
Said costar Preston Bailey, 8: "I think it's very interesting for a brother and sister to marry. It's a good thing that they're not brother and sister in real life."