Nope. During Star Wars, Vader and Anakin Skywalker were not the same person. "From a certain point of view" is an after-the-fact explanation, trying to turn a plot hole into an ace-in-the-hole.No, it turns out that Obi-wan told a fib because if he told Luke the truth, he would have crushed the boy's spirit. The boy wasn't emotionally mature enough to deal with the fact that his father's betrayal and descent into evil. That doesn't change that Obi-wan's honorable status, much less being one of the great Jedi. Even Vader still respected him twenty years later.
Besides, a man of honor will still tell lies. Obi-wan was thinking of Luke's welfare and emotional being, by telling him a half truth. Believing that once he was trained, he would be ready for the truth and could accept it. Note that when he's told, he refuses to believe it even when Vader tells him that he knows it is the truth. Later on, Luke is finally able to accept the truth which is what Vader comments on when they meet again.