Why did Brandon Marshall say sorry to Sapp?

From Comcast SportsNetLAKE FOREST, Ill. (AP) -- Brandon Marshall wishes he would have just stayed quiet. So he'll chalk up this spat with Warren Sapp as a learning experience.The Chicago Bears receiver apologized for retaliating with some harsh comments after being called a "retard" -- even though he wasn't backing off what he said."I really meant everything I said, but I think it would have helped (Sapp) more if I would have kept it private," Marshall said Thursday. "I apologize to Warren Sapp for saying that publicly. Like I said, I meant everything I said, but where I'm at in my life, you know, I need to learn from that and keep that privately."Marshall has acknowledged receiving treatment for borderline personality disorder and anger management, and after Sapp called him a "retard" in a radio interview, he didn't hold back.He said in an online video posted Monday that he couldn't discuss finances with Sapp "because he filed for bankruptcy" or marriage "because he filed for divorce." He also said in the video on that he couldn't speak to him about becoming a father some day because "he's not active in his children's life," and he posted on Twitter later that day that Sapp apparently challenged him to a fight.On Thursday, Marshall said he had exchanged emails with Sapp, an NFL Network analyst, before posting the video and that it didn't go well. All that stemmed from an interview with the syndicated "The Dan Patrick Show" in which Sapp ripped today's players in general for not respecting the past and teed off on Marshall in particular for "talking about Shannon Sharpe" for apparently not realizing this: "He's the first 100-catch receiver (tight end) back to back, retard."It appeared he actually confused Shannon Sharpe with his brother Sterling, an NFL Network analyst who had questioned Marshall's effort in the Dolphins' loss to the New York Jets a year ago. Marshall responded at the time, saying the commentators need to stop worrying about stuff they know nothing about.But the spat was just the latest round of drama for a player who just can't seem to avoid it. Marshall came to Chicago with a checkered history and found himself in the headlines when a woman accused him of punching her in the face at a New York City nightclub. His attorney said that was not true, and nothing ever came of the incident.Now, this."Some people say I have the talent to do that job when I'm maybe done, but it will be really tough for me because I know that when it is all said and done, I wasn't perfect," Marshall said. "I didn't play perfect football. You definitely have to criticize and give constructive criticism, but when you criticize guys like you've never made mistakes before, it just puts you in a bad position. I wish there was another way to do it. I know there is another way to do it, but would expect a lot from guys that have played the game before and understand how tough it is mentally and physically week in and week out. So like I said, we definitely need to use our words, whether you are a football player or not, to uplift and not to destroy because our tone is so powerful."