We broke the story ... Chiesa sued Conor over the injuries he suffered from the April 5, 2018 incident at Barclays Center where McGregor threw a steel dolly at a bus packed with UFC fighters and staffers, including Chiesa.

Chiesa was hit by shards of glass and suffered cuts to his face that were so bad, he was forced to pull out of his UFC 223 bout against Anthony Pettis.

Now, McGregor has filed a response to Chiesa's suit admitting his conduct was "unquestionably inappropriate," but should not be considered "outrageous."

So, why does that distinction matter? Because proving "outrageousness" is essential for collecting damages when it comes to intentional infliction of emotional distress.

McGregor also argues that his actions were "clearly not directed at [Chiesa] at all" -- which the judge should consider in evaluating the "outrageousness" of the incident.

Conor has publicly acknowledged that his target was Khabib Nurmagomedov -- who was also riding the bus that day.

Conor had flown into New York from Ireland to attack Khabib after the Russian fighter got into it with one of Conor's friends days before the bus attack.

In his court docs, McGregor also claims Chiesa has failed to prove that he suffered any real emotional distress from the incident -- noting that he's a "seasoned combat sports fighter" ... and therefore should be used to physical trauma.

McGregor was arrested for the incident and later pled guilty to disorderly conduct. He was sentenced to 5 days of community service, and ordered to complete an anger management class.