As I understood it, Grant actually sent TWO orders to Wallace, and somehow the second got there first, and (memory fuzzy) but as I recall Wallace actually turned his column around twice.
According to the Wikipedia article, there were three!
Personally, I look at it like this. He was in a tough place and had to make tough decisions. His only real mistake was not just countermarching, but, sending his lead unit back to lead the column back the other way. He wanted his best unit on point, and, so, history was made.
AS it was, his troops, while tired from marching, were fresh for battle and it may have saved the Union Army’s Bacon.....hmmmm bacon.