Chiellini has been hammered for his slip which allowed Borussia Dortmund to score in Juve's Champions League win.
Legrottaglie told TuttoMercatoWeb.com: "One slip can not be predicted or avoided, and it just happens: the field was wet, the cleats have not taken hold and he fell.
"These things are part of the trade, with all that, you can not blame Chiello for a crash. It can happen. Miss a ball and you're slaughtered, it is not consistent feedback from those who understand football.
"Those who know football do not judge the episode but the whole game, that's a mistake not caused by a lack concentration."