the sort of tangled sentence that can't really be sorted out by commas, I think. In writing, the author ought to sort it out. In speaking, in real life, people do get their tongues in a twist - but in real life you'd be able to see Hilary.
I learned more about English usage from reading "The Complete Plain Words" by Sir Ernest Gowers than I ever learned in all my days at school. Yet I don't recall him even mentioning a fallen subjunctive. He was brought in by the Treasury to write a guide for civil service officials, calling on them to do away with overblown, pompous and ill thought out writing. His motto may well have been,"Say what you mean in the least number of words". For those with any interest in English usage, his book is entertaining and well worth reading, and can be read online at...