Judge Mahon made a settlement for £20,000 with Revenue Commissioners over 10 years ago. To lose one chairman could be regarded as a misfortune for the planning tribunal, to borrow the words of Oscar Wilde, but to lose two would look like carelessness.
For this reason alone, Judge Alan Mahon will probably soldier on - and be allowed to soldier on - in spite of the revelation that he made a settlement for £20,000 with the Revenue Commissioners when he was a senior counsel over a decade ago.
The tribunal - indeed the tribunal system in general - already had enough problems before today's disclosure in Phoenix magazine. To the structural problems of slow progress and huge costs, as well as the farrago over the retirement of Mr Justice Flood over the summer, must now be added the issue of a tax default by the present chairman.
The planning tribunal needs every ounce of good standing and respectability it can summon in order to wage its battles against the massive resistance put up by the forgetful, unco-operative and often plain dishonest witnesses that constantly cross its path.
Yet Judge Mahon's tax problems could diminish and, in the eyes of some, damage his moral authority to preside over such matters. After all, in its six years of its existence, the evasion and avoidance of tax has been a central theme in the work of the tribunal.
Indeed, the large amounts of money coughed up by those under investigation has become something of a raison d'etre for the continued existence of the tribunal. As Mr Justice Flood proudly noted in his interim report last year, more than €34.5 million has been paid to the Revenue and the Criminal Assets Bureau in connection with tax compliance issues arising from the tribunal's work. Without this offset, the tribunal's massively escalating costs would be virtually impossible to justify.
Now it has emerged that the chairman of the tribunal himself was negligent in his tax affairs, and this problem only emerged when he was pursued by the Revenue Commissioners by way of audit.
Judge Mahon has explained his settlement by saying he "miscalculated" his tax liability in one year. Certainly, in his defence, the amount involved, and the proportion of this accounted for by penalties and interest, is relatively small by the standards of the list published by the Revenue Commissioners in their 1992 report.
However, Revenue sources say the matter was still a serious one because it was not disclosed by the taxpayer. Taxation experts also say that although barristers are self-employed, it is unusual for them to feature strongly on the defaulters' list. This is borne out by the fact Judge Mahon is one of the few barristers named by the Revenue in that year.
It was ironic that the news should break on one of the tribunal's big days, when the public gallery once again resounded with shocking allegations of illicit payments. For the first time, a witness declared a large payment to Mr Liam Lawlor and did not try to claim it was a political donation.
Candidates for judicial office are required to submit a tax clearance certificate to show that their affairs are in order, and Judge Mahon presumably fulfilled this requirement.
But while he deserves credit for declaring the matter to the Judicial Appointments Advisory Board when he applied for a job with the tribunal, this only raises further questions about the appointment procedure.
Given the composition of this board, which included the Attorney General and several nominees of the Minister for Justice, the question arises as to whether the Government was aware of the tax issue when they appointed Judge Mahon (who was then a senior counsel) to the Bench and the tribunal and, later, as chairman of the investigation.
Judge Mahon has impressed as a fair but firm chairman in his first months in the job. He has shown he has a sharp mind and a keen eye for the inconsistencies and contractions delivered by witnesses, and has not hidden behind bland language.
Liam Lawlor, in particular, has felt the lash from the chairman, as he denounced the politician's "sham" arrangement to cover up land deals.
No wonder then, that Mr Lawlor, speaking from New York, could not resist advising the judge to "let him who is without sin throw the first stone".
That won't be the last Judge Mahon will hear along those lines.
