Brought in as part of a boardroom rethink in the wake of some accounting anomalies that had been found in McCann Erickson's European operation, his job was to rebuild the holding company's financial standing. Meanwhile, the Securities and Exchange Commission began to make inquiries into IPG's accounting practices.
That was 2002. Five years on, and the SEC inquiries have long been a full-blown investigation. The results, still pending, will be fascinating; but waiting for them has become akin to watching paint dry - for everybody but Roth, that is.
Those five years have been critical to him. He has been methodically rebuilding IPG's financial standing with a meticulous dedication that has at times seemed ill-advised.
So determined was he and his team to get IPG's numbers in order, he delayed releasing results in 2005, for instance. Meanwhile, in the UK, remember how IPG's Initiative surprised clients, including Tesco and Weetabix, by handing them back millions of pounds in volume bonuses? IPG's clean-up policy, for a while at least, seemed to be shining a sometimes unnecessary spotlight on to its flaws.
But now, with a High Court case against the holding company planned for mid-October, we can see method in the madness. Barnett Fletcher's legal team will fling uncomfortable allegations about IPG into the public domain. IPG will be hoping that, whatever the court decides, its impeccable attitude towards finances since Roth's arrival will offset allegations about its previous accounting shortfalls.
IPG's best hope hinges on its clients and investors feeling that any allegations of wrongdoing can be consigned to history. The court case it is facing, not to mention the yet-to-be-revealed findings of the SEC, will test that strategy.