The first example of Victor's passion leaping over his sense of responsibility is the fact that he created the monster in the first place.  His passion for science and he desire to pursue the origins of life led to his tireless work on the patching together his creature.

Collecting cadaver parts from graveyards, he slowly pieces together the form of a human being. It takes him two years to complete his experiment, but when he finally gives his creature the spark of life, Victor can only run in fear. 

Victor is so hasty in his reaction to the hideous creature that he abandons him like a newborn with no knowledge of how to care for himself.  His emotional reactions tend to come in burst of passion that often lead him to make terrible mistakes of judgement.

"I saw—with shut eyes, but acute mental vision—I saw the pale student of unhallowed arts kneeling beside the thing he had put together. I saw the hideous phantasm of a man stretched out, and then, on the working of some powerful engine, show signs of life and stir with an uneasy, half-vital motion. Frightful must it be, for supremely frightful would be the effect of any human endeavor to mock the stupendous mechanism of the Creator of the world." (Shelley)

After he settles his nerves in looking at the monster, he realizes that the creature deserves a measure of happiness and Victor agrees to make the monster a female companion.

Again, in a burst of passion, rather than considering logically the situation, Victor decides to get rid of the partially assembled woman, he takes the unfinished body and drops it into the sea, without giving thought to how the monster will react to his hasty actions.