It depends on whether your definition of a flagrant grammatical error includes colloquial usage (since 1829!) as documented by, say, The Oxford English Dictionary:
personal
ADVERB
colloquial. to take (something) personal: = to take (a thing) personally at personally adv. 3c.
Source:
Oxford English Dictionary (login required)
Here are a few OED attested usages, including the earliest offered:
1829 Oh! if you'd call anybody a contemptible fool—I
don't take it personal—I think I had better adjourn. —E. Fitzball,
Flying Dutchman ii. iii. 31
1845 If my gun did not snap, call me a coward, and I
won't take it personal. —T. B. Thorpe, Big Bear of Arkansas 27
1938 Lem's different. He takes things personal. —M. K.
Rawlings, Yearling xvi. 186
You might be old, but probably not that old.