Paul Callan is a CNN legal analyst, a former New York homicide prosecutor and current counsel at the New York law firm of Edelman & Edelman PC , focusing on wrongful conviction and civil rights cases. Follow him on Twitter @paulcallan . The opinions expressed in this commentary are his own.

(CNN) Michael Cohen, often described as Trump's "fixer," "bagman" and "pitbull," just fired a warning shot at President Donald Trump. He also sent a message to federal prosecutors, who seem intent on changing his address to a federal correctional facility.

In an interview with ABC News anchor George Stephanopoulos, the wounded Cohen stated he will not be a "punching bag" as part of anyone's "defense strategy" and that his prime loyalty is to his "family." His words sounded like the angry rant of a man abandoned and betrayed by Trump, his beloved mentor, patron, and President. The words also implied -- that in the absence of a presidential pardon -- he may "flip" and testify against his former boss.

The real question is whether Cohen has anything valuable to trade for a deal with the special counsel, or whether his rambling threats inadvertently reveal that he is holding the "dead man's hand" of aces and eights.

Cohen has always basked in his reputation as the lawyer who was so close to and respected by the President that he was assigned the task of raining legal destruction on Trump's enemies. And many of Trump's opponents believe that, because of Cohen's alleged role as the President's legal hatchet man, he must know where all the proverbial bodies of the Trump Organization (and possibly administration) are buried.

However, Cohen's recent statement suggests that he has little useful information to trade. People with good information for a prosecutorial deal customarily bargain quietly, using experienced and competent counsel. While Cohen has reportedly hired a very well-respected and experienced defense counsel, former Assistant US Attorney Guy Petrillo, the attorney has yet to formally enter the case. In fact, Petrillo may well be groaning at Cohen's ham-handed approach to the federal prosecutors and the President.

Furthermore, Robert Mueller has already signaled that he turned the Cohen investigation over to federal prosecutors in the Southern District of New York. This suggests that Cohen's personal business interests are most likely the focus of the Southern District investigation -- rather than any potential collusion with the Russians.

In his ABC interview, rather than confirming his usefulness to Mueller, Cohen managed to distance himself from involvement in and knowledge of Russian collusion by stating that it was a "mistake" and a demonstration of "poor judgment" for high-ranking members of the Trump campaign to confer with Russian nationals during the now-infamous Trump Tower meeting.

"Poor judgment" would appear to be a subject of special Cohen expertise, given his bumbling $130,000 payment of borrowed hush money to Stormy Daniels. The action has resulted in Daniels becoming the most famous adult film star in the world, boosted by her lawyer who has been on television so much he probably has a reasonable shot at replacing Drew Carey on "The Price is Right."

The information Cohen revealed in his interview was also, no doubt, intended as a warning shot across the president's bow. Throughout the interview, Cohen made statements that placed him at odds with both Trump and his administration. He stated that he "repudiates" Russian interference in the American elections, dislikes the term "witch hunt" and isn't very fond of Vladimir Putin. He endorsed the "intelligence agencies" and the FBI that the President and his supporters suspect of "deep state" conspiracies. In other words, Cohen sounded primed to talk to federal prosecutors, unless, of course, he is pardoned by a grateful president for keeping his silence.

Cohen's anti-Russia sentiments suggest that he would be the last person Trump would consult regarding Russian electoral collusion or obstruction of justice. In fact, the difficulty that Cohen reportedly had in reaching his client, the President, to report that it was necessary to pay a porn star $130,000 to ward off the threat of a scandal during the closing weeks of the presidential campaign indicates that Trump had deliberately distanced himself from Cohen to insure "plausible deniability" of any Cohen misdeeds. Under the circumstances, Cohen would have little of value to trade with Mueller for leniency.

His only hope is to obtain a presidential pardon. But why would Trump bother, given the layers of "plausible deniability" that Cohen himself created to protect the President from allegations of porn star liaisons? The other problem with an immediate presidential pardon is that the immunity conferred by the pardon would deprive Cohen of his ability to assert the Fifth Amendment in the face of a grand jury subpoena. A subpoenaed witness can only assert the Fifth and remain silent if his testimony could link him to a prosecutable crime. If Cohen had previously been pardoned by the President for all potential crimes under investigation, the law will not permit assertion of the Fifth, because he cannot be prosecuted. Ironically, he can only be compelled to testify against the President if he is pardoned by the President.

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If, after receiving a pardon, Cohen is forced to testify and commits perjury to protect the President, he could be then prosecuted for that new felony. Should the President choose to grant a second pardon, this time for Cohen's perjury, he would surely face impeachment by an angry Congress -- just as Richard Nixon did.

Accordingly, the smart move would be to delay pardoning a loyal Cohen, at least until after his trial and conviction when the Mueller grand juries have been disbanded and their investigations concluded. In that scenario, Cohen would never be forced to the witness stand and therefore could never implicate the President. He could then be pardoned by the President, reimbursed for his crushing legal expenses and fade into obscurity.

Whether cooperating with Mueller or hoping that loyalty will be rewarded with a pardon, the road ahead is a rough and perilous one for Cohen.