When does the remainder-man becomes the legal owner - on the day of deed or day of death of donor/grantor/life tenant?

n piece county WA - if a son transfer his free and clear ownership of his home to his senior citizen mother as a gift but retains life estate in the deed..---

The mother (grantee) becomes the legal owner the same day or she becomes the owner day after the death of his life tenant son?(grantor)

In other words - son becomes judgment proof on the day of deed(he does not have other assets) or he is still considered the owner until his death and people/lawyers can sue him for civil damages ?

What are the advantages and disadvantages of retaining life estate vs free and clear transfer deed as gift