I expected better from that man! The atrocious spelling of English is due to the history of the words, and indeed how a word is spelled often tells where the word comes from and where its meaning comes from. Which makes studying language so interesting. The "gh" in the example-- is where English took an actual sound from related languages (ch as in the end of the Scottish word "loch") became an "F" sound later. In Dutch you still see these spellings:
I forgot to share a funny story with you. You know the great George Bernard Shaw. He has wanted to reform the English alphabet to be a phonetic one. He described the need of reform with the word "GHOTIO" which should sound as [fiʃ].