When Draco spoke Rodolphus turned and glared at him. It was rather odd that a man who wasn't above torture actually had some lines he didn't feel ought to be crossed. Thievery was one of those because it served no purpose in his life. "You're suggesting that we take what what we want?" He chose to focus on the situation rather than any personal relation that might be present.
Honestly, the moral of this place were so skewed. Taking what you desired without proper agreement was permitted but civil disagreement solved under completely normal and agreed upon circumstances was not.