ST. LOUIS The 49ers probably would have won in regulation Sunday if not for a third-quarter safety that had them continuing to wonder what happened well after the game.
On the play, quarterback Colin Kaepernick retreated into his end zone and, with two Rams defenders grabbing at him, hurled the ball downfield. The pass landed out of bounds but appeared to go beyond the line of scrimmage, which is one of the criteria for avoiding intentional grounding.
"I thought I was outside the tackle box," Kaepernick said. "I thought I got it past the line of scrimmage."
After conferring, however, the officials penalized Kaepernick for intentional grounding, which, because it occurred in the end zone, resulted in a safety.
Jim Harbaugh said he didn't understand the call. He also said he was told he couldn't challenge it because it was a scoring play.
After the game, however, referee Carl Cheffers said the play wasn't reviewed because it was a judgment call. Cheffers said that in the judgment of the official on that side of the field, the ball did not cross the line of scrimmage.
Under league rules, a pass is deemed to have crossed the line of scrimmage even if it lands out of bounds.
"No aspect of that is reviewable," Cheffers said. "The result of the play is not a scoring play; it's a penalty enforcement that results in a score."
Dwindling receivers Already without wide receiver Kyle Williams, the 49ers saw another wideout, Mario Manningham, go down with an injury in the fourth quarter.
Manningham already was on the team's injury report because of a sore right shoulder and seemed to aggravate the ailment. Harbaugh said he didn't know whether Manningham, who left the game with five catches for 37 yards, will be available Sunday against the Dolphins.
If Manningham is not available, the 49ers will have only four wideouts.
Williams was placed on injured reserve last week after tearing an ACL against the Saints. The team's healthy wide receivers are Michael Crabtree, Randy Moss, Ted Ginn and A.J. Jenkins.
Jenkins, the team's first-round draft pick, was in uniform Sunday for the second time this season. As in Week 1, Jenkins did not play.
Backup Brandon With Kendall Hunter (Achilles) out for the season, veteran Brandon Jacobs served as Frank Gore's primary backup. Jacobs ran four times for six yards.
Second-round pick La-Michael James was inactive and has yet to be in uniform this season.
Gore, meanwhile, carried the ball a season-high 23 times for 58 yards against the Rams. He had 21 carries in the previous game against St. Louis, which also went to overtime.
Et cetera Aldon Smith has 171/2 sacks this season, tying a franchise record set by Fred Dean in 1983. Smith is gunning for the NFL season record of 221/2 sacks set by the Giants' Michael Strahan in 2001.
After the 49ers were penalized 10 times for 68 yards last week against the Saints, Harbaugh said fewer penalties would be a focus the following week. The result: San Francisco was flagged a season-high 11 times for 97 yards.
The Rams' win broke a 61-61-3 tie in regular-season games between the teams. The first game was played on Oct. 1, 1950.