SJSinNYC, certain lenient opinions are beyond something one can rely on. Sometimes, some people do things just because they want to, and not because they have a certain lenient opinion in mind. Generally speaking, there are Halochic rules as to which opinions one can rely one. One can not just grab a lenient opinion from some place and go act on it.
A be’shogeg person being awful? How about a fellow who batters his wife, but he does not know it’s assur?