I saw a phrase like this the other day.

Problem:
The possessive preposition “of” before a noun should not be used with a possessive apostrophe-‘s’ after the noun.

Explanation:
The phrase “friend of somebody” translates to “somebody’s friend”.

So, “friend of Jim’s” would translate to “Jim’s’s friend” — a meaningless concept.

It seems that the author fell prey to hypercorrection, using both the possessive preposition “of” AND the possessive apostrophe-‘s’ to indicate friendship with Jim.

Solutions:
“friend of Jim”
or
“Jim’s friend”