There's a very strange perception of how foreigners pronounce Japanese names. It stems from the fact that Japanese vowels are very short compared to English vowel sounds - and they're completely unstressed when spoken. Thus, when we English speakers say things they are super sensitive to the vowels - they just sound absurdly, comically long and emphasised to them. If you go anywhere in Japan on the train you'll hear these voices announcing stations in various languages, and when it get to English it's outrageously overpronounced, every time. Some people have embraced it, introducing themselves with "English pronunciation" when speaking to foreigners, so that "Narita" becomes "naREEEta," "Iguchi" becomes "iGOOOchi," and so on, nearly always placing incredible strength on and lengthening the second vowel. That's what happened here with Sakamoto.
EDIT: I'm not defending the wacky pronunciation, just explaining why the Japanese executives would insist on something that seems so crazy at first glance. This is how they think Americans pronounce stuff, because they perceive it as being exaggerated to that same degree even when it isn't actually that bad.
