All it means is that Anakin allowed his emotions to block his Judgement. He was pissed, thrown into an un-controlable rage, and he did the only thing his confused and twisted mind could think of to do.
He feared loss, and he hated it when things were unjustly taken from him He allowed his emotions to control him, instead of him controling his emotions. Which is Exactly why Obi-wan was always lecturing him and keeping him down throughout the entire movie.