Question about an obese person I know?

Okay we have a family member who is maybe at least 400 pounds. Anyways I just really feel bad for him. He never gets to leave the house due to his size and medical problems. Well tomorrow my mom invited him over for dinner and later cancelled plans with this person . She said to me the reason why she cancelled she doesn't want him breaking and ruining her car due to his size. She also warned other family members as well not to pick him up because the might break there car too. It just made me so mad that she is treating him like a piece of trash especially he never gets to leave the house.. I couldn't even imagine how he feels. Do you think my mom has a point and I'm being ridiculous? Or is she being totally wrong? Thanks guys!!! Sorry for the typos!