No, the prosecutor won't pay much attention to what you and I say on any forum UNLESS you or I are the suspect in his case. In this day and age investigators and prosecutors usually look at social media and on-line forums to see if their subject has made relevant statements and will certainly try to introduce them into evidence at trial.
In line with Mary's comments, I strongly recommend that martial arts students research their own local laws regarding self defense. Some states establish a duty to retreat while others don't. There is no simple explanation that cuts across all jurisdictions. You simply have to know and apply the law in your jurisdiction in a situation like this, or you are in grave danger of running afoul of the law even if you feel your actions are reasonable.
I agree that comments made by strangers isn't likely to impact a case like this. I know from my training that a common statement during tanto tori is..."he stabbed himself." The statement the guy in the article made...."he ran onto the knife" This statement alone, in my opinion, would be cause for closer scrutiny. No one just runs onto a knife, as if to stab himself. That would be silly. It seems to me that the Aikido community has that phrase in their vernacular. It probably isn't the best thing to say.