I wouldn't consider it disrespect if my slave respectfully corrected an error.
Example
M: I have to be ready for my meeting with Master A_ at two o' clock.
S: Pardon, Master, but today is Tuesday. Master's meeting is on Wednesday.
M: So it is.
Once they have done so, they had better be able to prove it.
As for approach, once again , with respect and they better be right.
Of course I always think of slavery as a close relationship. In a larger household I would probably have a trusted slave(s)who had proved faithful who would manage my house including my slaves and that one would get a lot more latitude. The rest would report to them and had better stick to their function unless it was something serious or the steward referred them to me, though they would likely handle the solution. I would not tolerate disrespect from a slave I had no relationship with. The most likely would be my steward, housekeeper, and my body slave. Out of those the only naughty one should be my body slave, who would also be my bed slave. The statements I've made would apply to her best. As for discipline, I would start light and increase in severity until I got results. I wouldn't spend a lot of time on "livestock".