CeeDee Lamb found himself in a rare situation during the Dallas Cowboys' preseason game against the Los Angeles Rams this week. Despite not even suiting up for the game, he was still penalized for an issue on the sidelines with a referee.An official was running along the border out of bounds during a play in the game when he crashed into Lamb in front of the Cowboys' bench. After the superstar wide receiver took a legitimate hit, he was then flagged for sideline interference.NFL referee Alex Moore was recently asked about the situation in an interview with PFWA Pool Reporter Gary Klein. He was asked to specifically describe what happened and why it was a penalty.Moore explained:"It's a sideline interference. CeeDee Lamb was standing in the restricted white border area, which is our area to officiate the game. The official on the play was focused solely on doing his job and he ran into CeeDee Lamb, who was standing in that restricted area. That's what happened, and with that contact, it's an automatic foul."Moore was then asked how often he's encountered this situation, to which he replied:"It's more of a rare situation. Normally, we don't have anybody standing that deep into the restricted area, or that type of forceful contact. So, it is a rare occurrence, but it does happen from time to time."Moore was then questioned if the Cowboys were on the same page with the call, to which he responded:"Absolutely. It's something that everybody is aware of. That white area is our area to work safely."Lamb was cheering on the Cowboys' offense during the play before being collided with from behind by the referee. It appeared to be an honest mistake by Lamb, but the official rules clearly indicate he committed a penalty.Thankfully for the Cowboys, Lamb reportedly came away from the situation without any injuries. Despite the penalty, it occurred during the preseason, where the results of the game don't affect the outcome of the season.Why didn't CeeDee Lamb play for Cowboys in preseason against Rams?Lamb sidelinedThe Dallas Cowboys opted not to play many of their starters in their preseason game against the Los Angeles Rams this week. In addition to CeeDee Lamb, many others were inactive, including Dak Prescott and George Pickens.This has been a common strategy for many NFL teams during their preseason, as their main focus remains to keep their stars healthy for the kickoff of the regular season. Their next preseason game comes next week against the Baltimore Ravens, so it will be interesting to see if they continue to rest their key players.