Jones pleaded guilty to several breaches of the SANZAR Code of Conduct after his criticism of referee Matt Goddard during the game at Suncorp Stadium.
SANZAR had recently announced zero tolerance on criticism of referees and indicated Jones faced a hefty fine and/or a suspension from coaching.
However, Willis took into consideration Jones' guilty plea, his undertaking to comply with the SANZAR code of conduct and his agreement to provide a written apology to Goddard when deciding a fine was sufficient punishment.
Jones had stated earlier this week that he was standing behind his statements and called for the referees themselves to be put under the spotlight like coaches and players are after matches.
"All we're asking is for the process to be due, consistent and legal," Jones said.
"Every part of our game is under review. Coaches are under review all the time, players are under review all the time and we must have a forum to review referees as well.
"The only concern I have is doing the right thing by my team. I think I'm doing the right thing by my team and I'll continue to do so.
"I've got a duty as a coach to support my team and ensure that we get a fair go."
The fine is to be paid to a local charity - the Spinal Injuries Association of Queensland - within 28 days.