He was joking.
And while English is a Germanic language, you can't just pretend that English is a direct descendant of Proto Germanic. Modern English didn't come straight from Anglo-Saxon and evolve in a vacuum. Norman French played a huge role in forming Middle English, and its effects are still very present in the English language today. To say that modern English is a direct descendant of Proto Germanic is, at best, misleading, because modern English is also a direct descendant of Old Norman.
And you can't just say that English "borrowed words" from French. When Middle English was being formed, modern French did not exist. Modern English does contain many words of Norman origin that date back to Anglo-Norman and Middle English, but not modern French.