Per that report:
"Elliott was briefly detained by police, however a player can be subject to penalty under the personal conduct policy without an arrest. Elliott was suspended six games in 2017 under the personal-conduct policy, stemming from an alleged incident in 2016 involving a former girlfriend in Columbus, Ohio, but he was not arrested or charged by police."
In May, Elliott was seen on video having an argument with a woman, blocking her walking path on several occasions. The video then cuts to him getting in the face of a security guard before putting his body into the guard and using his forearm to push him into a metal grate, knocking the guard to the ground.
Police then came to the scene, handcuffing the running back, though he wasn't arrested or charged in the incident.
Charles Robinson of Yahoo Sports reported in May that Cowboys owner Jerry Jones didn't believe Elliott should, or would, be disciplined by the NFL for his conduct in Las Vegas.
"I don't see that having any consequences for us," Jones told reporters at the time.
However, Elliott reportedly has been put on notice by the NFL after his previous six-game suspension as well as a separate incident in which Elliott was seen on video pulling down a woman's shirt and exposing her breast during a St. Patrick’s Day parade.
As Robinson wrote, the NFL has kept open the possibility Elliott could face punishment for any additional situations involving the police:
"When Elliott's suspension appeals had run their course, a vaguely worded determination was relayed to the running back and his representatives that he could be subject to further discipline for additional contact with authorities. However, it was not spelled out what the threshold would ultimately be to trigger another personal conduct violation. Essentially, it would be up to Goodell to determine if Elliott had triggered a violation—and that determination would be made on an incident-by-incident basis rather than hardened guidelines."
Elliott, 23, is one of the league's best running backs and offensive players, rushing for 4,048 yards and 28 touchdowns in his three-year career. If he's facing another suspension, it would be a major blow for a Cowboys team with Super Bowl aspirations in 2019.