Dear (Whatever)
Please accept my apology for engaging you in debate about our recent project and for whatever inconvenience this may have caused you, but I felt that your instructions differed from what I understood them to be. It seems that our recent conflict was a result of miscommunication; as I am not always aware of changes in instructions.
It is certainly not my intention to be confrontational. In the future I will endeavor to notify you if I am unclear as to your initial instructions. Please know that I value our working relationship and hope that it remains intact.
Sincerely,
Please accept my apology for engaging you in debate about our recent project and for whatever inconvenience this may have caused you, but I felt that your instructions differed from what I understood them to be. It seems that our recent conflict was a result of miscommunication; as I am not always aware of changes in instructions.
It is certainly not my intention to be confrontational. In the future I will endeavor to notify you if I am unclear as to your initial instructions. Please know that I value our working relationship and hope that it remains intact.
Sincerely,