I think Ramos got yanked purely because of "the book," which, yeah, isn't of any use if your lefty relievers aren't good. But, as with most managerial decisions, you get toasted or roasted either way. And Bruce already had a home run against a RHP in the game. If Ramos had stayed in and given up the HR we'd not only be complaining that he was rattled but questioning why Bowa didn't bring in the lefty.
And the main thing is, Ramos allowed the winning run. Arguably even starting Cabrera off 1-0 was costly, and certainly the whole distracted AB was. He lost the game (literally).