That's not an improperly annealed coin. It doesn't display any of the characteristics of on on the obverse or reverse and the edge should be bright and clean because while the improper annealing remains after the strike on the obverse and reverse, to put the Reed in on the edge with the collar it's completely obliterated on the edge and appears BU there.
Only way to really know with 100% certainty is to send it for grading and have it attributed as that, and see if they agree, but from my opinion and what I know on the subject this isn't one, not even a 1% chance of being one it's nothing like you'd expect to see, you can look up graded examples of Kennedy half that have been improperly annealed and see how they are, but be aware the unslabbed graded examples I've seen online are environmental damaged coins. The improperly annealed coin always has a really bright reeded edge compaired to the obverse and reverse because the collar wipes out the remnants putting the Reeding on, while the strike just smashes it in on obverse and reverse.
In most all cases they are found in the year they were struck from new coins and sent for grading so there isn't much of a possibility of tampering to get the effect. The longer they circulate the less likely they will get attributed as improper Anealled and more likely it gets attributed as environmental damage.