Simple. Because his own law firm would not dare to do it.
Sullivan and Cromwell probably told him they'd sue him for defamation if he released such an opinion in their name.
Ackman does NOT have a legal opinion. Period.
Icahn called him out. Icahn asked him for it. So far, SILENCE.
Ackman pushed HLF management to answer ALL HIS QUESTIONS in 24 hours. He advocated TOTAL TRANSPARENCY - for all other people except him that is.
Yet, he does not answer ANY QUESTIONS other people posted to him. Funny, isn't it?