Sure - we can even stick to Sun Yang in the same event. Look at the difference in stroke technique in the beginning, mid and end. He starts asymmetric, switches to symmetric in mid, and finishes strong with asymmetric. Sun Yang Smashes Men's 1500m Freestyle World Record - London 2012 Olympics - YouTube
Most people, most of the time, swim asymmetrically (10k open water): Rio Replay: Men's Open Water 10km Marathon Final - YouTube
Compared to Sun Yang it looks sloppy, but you have to swim differently in waves.