[Toronto] Landlord wants me to pay for cockroach infestation

I left 2 months into my 1-year rent at a boarding house, where the landlord doesn't live there himself. I left because of extremely poor living conditions such as poor management of house cleaning, lack of ventilation, and lack of convenience in general. Part of the reason being that there are cockroaches starting to come into the house and especially my room since it's located right in front of the main entrance.

Now the landlord wants me to pay for the "damages" I presumably caused by "growing a cockroach infestation due to my lack of hygiene" when the entire house isn't managed properly by other housemates anyway. I have only reported the lack of cleanliness once to my landlord, but I am unsure if that changed anything.

Is the landlord really obligated to demand for payment? Sorry I'm new to this and is unsure of what to do.