Well it's a statistical oddity. For only two seasons, 1950 and 1951, the NFL wouldn't count yardage lost on sacks against a team's net yardage total. No one knows why.
Van Brocklin lost 13 yards on a sack in that game, which is why the Rams are sometimes credited with 722 yards and 735 by official records.
By 1951 standards of record keeping, 735 is correct. By the standards of every season since, 722 would be the number.
So one person could say the Rams still have the record, and another could say the Dolphins broke it. And both could be right.