If the path he choose was the best path, then remorse would not have been a usefull emotion. But regret still would have been.OneIsEros said:Remorse is repeatedly described as an obstacle to the path.
I suspect he wrestled with that obstacle a lot prior to his enlightenment. As described in the Pali literature, he probably would not have experienced remorse post-enlightenment.
You can not realy be an enlightened person if you are careless about other people's pain.
The difference between remorse and regret is that you can regret having been in the position where you had to make that choice. You can regret karma.