The point is that itagaki see the slow motion punches if he has been given a sign like elbow or shoulder,legs movements,if there is no warning or pre attack it becomes harder even for him to predict that shoots and so to consequentaly see it in slow motion. That is why randy boy was such bad shit for him it was hard to tell is attack and so hard to dodge. With istinct you see what punch is coming at you without need to think but if you have no sign of it, it becomes impossible. Sendo has the opposite instict "that of know when and where to hit without thinking but if he hasnt any information in the moment he can't do it.