Yes it was actually his mistake.because he became invisible,and also became more powerful as he was not seen by anyone,but he didnt use his power for good and needy things,instead he became mor greedy and started killing people who came in his way,he robed his father first who suicided
then the vicar's house
and then he also burnt down the hostel in which he lived
he had no humanity 
he experimented on the animals
these things prooved that he was not at all a human 
Yes ,,,,,,he misused his the answer is yes............. hope u lke it
             and happy holi my frd