Thin or fragile skin can occur for a number of reasons in elderly people. Sun exposure, genetics, prescription blood thinners, aspirin or anti-inflammatories such has ibuprofen are some causes. With the slightest scratch, the skin can tear and bleed.
This has happened a few times with my LO. Fortunately it has happened when I am close by. He will find me and show me the injury (usually an arm) . He is very matter-of-fact about blood running down his arm. No panic.
I find it is best to have cleansing wipes, antibiotic ointment or cream and bandages on each floor and in each bathroom and the kitchen. Also, if anyone else is caring for your LO (part-time caregiver, friend or family member), be sure to include bleeding procedures along with the other instructions.