The first time I heard it, was in a BBC documentary about old cars. The pronunciation was nowhere near /ɪˈpɪt.ə.mi/. I think it started with something like /ə/ instead, and that sound corresponds with way too many letters and I haven’t figured out how to make any sense of that.

Fortunately, modern tools will help you find the word you’re looking for, so knowing the correct spelling isn’t that critical any more. However, I was using a paper dictionary at the time, which explains why it took so long.