In case you've forgotten, here's what the president said about the pardon of his son in a statement.

From the day I took office, I saidI would not interfere with the Justice Department’s decision-making, and Ikept my word even as I have watched my son being selectively, and unfairly,prosecuted. Without aggravating factors like use in a crime, multiplepurchases, or buying a weapon as a straw purchaser, people are almost neverbrought to trial on felony charges solely for how they filled out a gun form.Those who were late paying their taxes because of serious addictions, butpaid them back subsequently with interest and penalties, are typically givennon-criminal resolutions. It is clear that Hunter was treated differently...

No reasonable person who looks at the facts of Hunter’s cases can reach anyother conclusion than Hunter was singled out only because he is my son –and that is wrong...Enough is enough. 

U.S. District Judge Mark C. Scarsi is the California judge who oversaw the Hunter Biden tax trial which ultimately resulted in Hunter Biden pleading guilty. Judge Scarsi was asked to dismiss the tax case in light of the president's pardon which gave him a chance to weigh in with his thoughts.

...the President asserts that Mr. Biden “was treated differently” from others “who were late paying their taxes because of serious addictions,” implying that Mr. Biden was among those individuals who untimely paid taxes due to addiction. But he is not. In his pretrial filings, Mr. Biden represented that he “was severely addicted to alcohol and drugs” “through May 2019.” (Disputed Joint Statement of the Case 4, ECF No. 152.) Upon pleading guilty to the charges in this case, Mr. Biden admitted that he engaged in tax evasion after this period of addiction by wrongfully deducting as business expenses items he knew were personal expenses, including luxury clothing, escort services, and his daughter’s law school tuition. And Mr. Biden admitted that he “had sufficient funds available to him to pay some or all of his outstanding taxes when they were due,” but that he did not make payments toward his tax liabilities even “well after he had regained his sobriety,” instead electing to “spen[d] large sums to maintain his lifestyle” in 2020.

NBC News backs the judge up on this point:

The taxes were eventually paid after federal investigators told Biden they were looking into his finances in December of 2020.

As for the claim that no reasonable person could see it otherwise, Judge Scarsi notes that two federal judges saw it otherwise.

According to the President, “[n]o reasonable person who looks at the facts of [Mr. Biden’s] cases can reach any other conclusion than [Mr. Biden] was singled out only because he is [the President’s] son.” But two federal judges expressly rejected Mr. Biden’s arguments that the Government prosecuted Mr. Biden because of his familial relation to the President... And the President’s own Attorney General and Department of Justice personnel oversaw the investigation leading to the charges. In the President’s estimation, this legion of federal civil servants, the undersigned included, are unreasonable people.

Special counsel David Weiss made a similar point about Biden's "no reasonable person" claim.

There has "never has been any evidence of vindictive or selective prosecution in this case,” his office's filing said. “In total, eleven (11) different Article III judges appointed by six (6) different presidents, including his father, considered and rejected the defendant’s claims, including his claims for selective and vindictive prosecution.” 

Judge Scarsi concludes:

The Constitution provides the President with broad authority to grant reprieves and pardons for offenses against the United States, U.S. Const. art. II, § 2, cl. 1, but nowhere does the Constitution give the President the authority to rewrite history.

The remaining two pages of Judge Scarsi's order read like an effort to embarrass the White House on a technical matter. A pardon can only extend to past crimes but Judge Scarsi notes that Joe Biden's pardon continues through Dec. 1, the day the pardon was issued. If that were true, Hunter Biden could have, in theory, robbed a bank later that day and gotten off scot free. So Judge Scarsi corrects the reading of the pardon to only mean up to the time it was signed.

The President signed the pardon on December 1, 2024. (Id.) Because the period of pardoned conduct extends “through” the date of execution, the warrant may be read to apply prospectively to conduct that had not yet occurred at the time of its execution, exceeding the scope of the pardon power. Under the canon of constitutional avoidance, the Court declines to interpret the warrant in that manner and instead understands the warrant to pardon conduct through the time of execution on December 1.

The stories I've read about this don't even mention this critique of the pardon. I suspect if Trump's White House had made a similar legal mistake and been corrected by a judge we'd be hearing a lot more about it.