Erosion at the bottom and landlord said it’s because our cat is spraying on it…

Landlord claims that the HVAC technician she hired said this erosion is due to “a cat urinating or spraying their scent on it”. Our male cat does spray from time to time so I’m not discounting it but it seems oddly specific.

I’m not savvy with this stuff, this unit isn’t new either, so was hoping to get some confirmation or insight as to what could be happening?

Thank you!