He totally does NOT say that.
Firstly, you're missing an "and". He's talking about people who break commandments AND teach others to do so. You completely left out the second condition.
Secondly, in the context that he makes this remark, he references the person being in heaven, but not looked favorably upon (as opposed to being in hell). Where he talks about someone being considered the least in the kingdom of heaven, you changed that to a pass/fail condition on getting through the gates.
None of us can say with certainty who is or isn't going to be in Heaven. The New Testament just lays out the advice and guidance for getting there. You can't read Jesus' teachings and then be able to tell someone they're not going based on the way they've lived their life (you can say it, but you can't actually know it).