Between bursts of heavy rain, I arrive at Cormac Mohan’s office overlooking Fitzwilliam Square. One of the best-known independent experts in the restructuring sector, he sits behind a large dark wooden desk — clear at its centre but piled high with papers at either end. Mohan employs 16 people, and it is just two weeks since the Scottish-founded accountancy group AAB, backed by Goldman Sachs Alternatives, announced it was making a strategic investment in his firm. It was one of three deals announced by AAB’s Colm Duggan, formerly a partner in Ormsby & Rhodes and now head of professional services…