The gemara starts a sugya on kuf gimmel amud alef that Rava made a beracha on the wine before the meal and then another beracha on the wine after he bentched. Rava explains his reasoning as doing like talmidei derav that bentching is a hesech hadaas. The gemara on kuf gimmel amud beis brings a story of Rav Acha the son of Rava who saw three chachomim do different things when making a beracha on the wine and whether bentching is a hesech hadaas. Rav Acha the sone of Rava then asks what should he do. What was his question and why didn't he just do like his father (Rava) who at the beginning of the sugya acted like talmidei derav?
The fact that someone's father acted in a certain fashion does not mean that he should rule this way for the public. Rav Acha's question, "We, what should we do?" was clearly a question regarding what the general Halachah should be, not a personal question regarding his own behavior in this manner (which incidentally does not have to be the same as that of his father).
All the best,