We had to change door handles also. Our female GSD Abby, who has since gone to the bridge from cancer, was able to open just about any door there was.
She even opened the door while my kids were playing in our fenced-front yard and I had run in to use the restroom. It just so happened in the really short time I was inside, the water meter reader came to read the meter. He came in our yard to read it while the boys were playing and my GSD didn't care for that.
She opened the door, chased him from the yard and bit his leg as he ran and flew over the fence (he didn't bother with the gate).
Of course, with all the barking, noise, etc., I was out there in a heartbeat, but one step behind the action. He was VERY cool about it - said he saw the dog watching through the storm door, saw my signs on the fence, saw the boys, but chose to come in the yard anyway. After all was said and done, while he was packing snow on his leg, even though I offered everything under the sun for it, he asked, "Did your dog open the door?"
I did send him a small Harry and David
gift fruit basket though, simply because he was such a good sport about the whole thing. The card read, "Sorry my dog took a bite out of your leg, here, take a bite out of this."
You might want to reevaluate teaching your dog to open the door. A bell hanging on a string works well.