The Jags went down 24-21 to their opponents in a match that will be remembered for the chaotic brawl.
Fournette left the Jaguars sideline to get involved after Dede Westbrook pushed Bills safety Micah Hyde.
A mass brawl then ensued with players from both teams getting involved were quick to defend their team-mates.
After the match Fournette did apologise for his role in the incident.
“You are going to have to rise up and also protect your own,” he said.
“At the same time, you can’t have that. I apologize to all the kids who look up to me and their parents.
“The biggest thing is, this loss [is] totally on me. I take [full responsibility].”
Lawson was not in the Bills’ dressing room after the match.
But coach Sean McDermott said he spoke to his player and doesn’t plan on taking any action against him.
“I’ll go back and look at it, but at the end of the day, a guy defending his teammate – and I’ve sat and already talked with Shaq, we do things the right way – but when people step up and challenge us, I don’t expect us to back down,” McDermott said.
And Fournette went on to say he was most unhappy with a fan confronting him.
“My biggest thing was when the fan hit me. I had a problem with that,” he said.
“… He [Lawson] was saying what he had to say. I really don’t care. Words are just words.
“They don’t mean nothing to me. Just got to move on.”
Fournette revealed he got angry when he saw Lawson push his team-mate Carlos Hyde, and that’s when he got involved by throwing aa punch at Lawson.
“I mean, that’s my brother,” Fournette said. “All of them are my brothers. I don’t know [how] y’all was raised, but that’s just me.”
The Jags are next in action against the Indianapolis Colts on Sunday at 6pm.