Nor is it a beef with Protestants. We honor Mary as well. What we don't do is elevate her to a near level of deification, as if, in life, she was given the power to determine whether she would bear the Savior. Yes she was obedient because, like many before her and after her, she was given the grace of God. Her acquiescense to the will of God never stood as a determining factor in the efficacy of God's eternal plan any more than, in death, does she holds the reigns or serve as the conduit or whatever other such nonsensical level of control you guys think she has over the dispensation of God's grace. She obeyed because God worked in her the desire and ability to do for His good pleasure.
Neither did Calvin. Neither do I. What's your point?
It wasn't an error. It was only an error to your denomination and the EO denomination, as you both place emphasis on the works of man and assume, wrongly, that such works lead to justification. Your works, none of them, none of the Pope's works, none of Peter's works, none of Mary's works, none of the head of the EO denomination's works, none of Michelle's works, none of Don's works could ever, ever contribute to justification as they are, of their own merit, filthy rags before God's righteousness. We are saved by works Michelle. It's just not our works that save us.