The formula for the tetraethyl lead production reaction is not quite right. The leading 4 is written as a subscript, but it should be full size. This might be a misprint in a real book.
Andrew Del Mar does indeed wrongly refer to Iranians as Arabs (they're Persians), but that was a common misconception in those days, and if anything this clearly scripted 'mistake' is actually quite fitting to the character.
Deakin, the observer lawyer at Nuremberg, says prisoners can't turn their backs to the cell door but Linz's desk is obviously setup that way even prior to his death.
Mrs. Knowles offhandedly says her husband had been at Bletchley during the war, as if everyone would have been aware of the code breaking operations that took place there during the Second World War. However, those operations were classified until the mid-1970s and Professor Knowles would have not been able to disclose what he was doing there to his wife under the Official Secrets Act.
Nothing in particular about kidney problems results in coughing. If anything, a person with kidney issues would rather want to avoid coughing, since any such sharp breathes (or deep, as the scene correctly states) would be quite painful.