yes, it definitely was really one sided after first 3 rounds and as you mentioned his ability to change to south paw, this what he basically did in the second or the third round and stayed in that stance for the entire match, he also added lateral movements, which made it even more difficult for postol.
At first it seemed postol might be exchanging and being aggressive for the early rounds and crawford couldn't adjust, but in reality those 3 rounds, crawford was assessing postols style and after in the 4th rounds, straight on the bell, knockout, which I felt was on the back of the head, but after crawford found his style and knocked himn out again in the same round, but this was very devestating on the chin, you could tell how he was viewing the world when he was retreating with his body and head at a slant angle, that he dizzy and would fall any moment.
At the last round, crawford stopped the lateral movements and indicated to postol, you want me, here come take your best shot at me, crawford to aggressive mode pressuring postol, making postol move back and be cautious about his next move.
This really was due to postol's lack of experience that lost him the fight, he was basically following crawford instead of cutting the ring and being tagged for it. Crawford managed to adjust nicely and had a nice counter attack and he was strategic and aggressive. You could see based on their stance and the way they were bouncing ,if you would say, that crawford was more relaxed while postol was not relaxed as much and wanted to find that knockout opportunity, his jab started to disappear later on. Till the last round postol turned aggressive and pressured crawford, which was a little too late and lost the fight.
Top rank mentioned that pacquiao will be fighting again on 5th november and he wants against the winner of this match, which is crawford, who when asked about it was acting like pacquiao was nothing and that he was willing to fight anyone his camp chose for him, playing it cool lol.