Apple does spend comparatively little on R&D (perhaps part of that is because they don't produce 400 different models of every darn device), but their margins on iPhones are still nowhere near 70%.
I was just speaking specifically the notion that Apple's margins as a company are eaten up by R&D spend which we agree they're clearly not. (The fact that they're doing multi-billion dollar stock buybacks and issuing increasing dividends show they have more money than they know what to do with).
Although since you brought it up, I did a quick search and found that the margins on the iPhone as an individual product (vs. the company's overall margin) are speculated to be near 70% and that figure isn't just pulled out of thin air: