The game was postponed after the 31-year-old defender physically confronted the match official, and the German side will now make an official complaint
After Fortuna midfielder Oliver Fink received a particularly late tackle from the Eagles' Javi Garcia, Luisao approached the referee and appeared to bodycheck him. The official remained on the ground motionless for a few seconds, and was eventually carried from the pitch.
Fortuna president Peter Frymuth was less than pleased with the Benfica players' behaviour, and threatened to liaise with the German federation and the European governing body about the incident.
"I'm shocked. I've been in football for many years and have never seen anything like it. I do not understand that players from a team with the reputation of Benfica, a team that play in the Champions League, have such an attitude," Frymuth was quoted as saying by A Bola.
"Let's get help from the German federation and talk with Uefa about Luisao, and about what other players of Benfica did. I hope they are severely punished.
"We should have been celebrating for ourselves, but we are now faced with a depressing action. We are speechless, we are dead with grief."
Frymuth also revealed that the referee refused to restart the game "because of the behaviour of the players of Benfica."
But the Brazilian international maintained his innocence post match, speaking of his shock that the referee had gone down so easily.
"I was surprised. I did not make any move of aggression. I tried to be ahead of my colleagues and I saw the referee fall. I tried to talk to the assistants still on the pitch to explain my intention," the defender was quoted as saying by Record.
"I do not fear anything. I have a clear conscience and I will continue with my work."
Subsequently, the event has been described as a "lamentable display of theatre from the referee" on the Portuguese club's official website.
The incident occurred in the 38th minute of the match at Esprit Arena, with the score still 0-0 when it was stopped.