A retired judge anecdotally thinks convict Donald Trump could have his head examined before he’s sentenced. When Manhattan Supreme Court Justice Juan Merchan sentences Trump on July 11, he apparently will have the discretion to order a psychological evaluation. “You have to also really understand this defendant, which means a judge has a right to require person to undergo a psychological evaluation,” retired California Superior Court Judge LaDoris Hazzard Cordell said while appearing on CNN’s “The Source” with Kaitlan Collins. “And given how unhinged and incoherent Donald Trump has been in spe…