Tinfoil hat conspiracy theory:

When the cards were made he also generated a bunch of legacy addresses for some other reason with the same keys.
Was planning on a 2nd round of scamming by having those addresses also get funded from some other project.
This way when the PKs were "compromised" all could be swept.

Now, the question is why did they get funded now? The other scam is now progressing and he is starting to fund them to sweep later.
Sell 500 of something funded @ $10 each. But only fund the 1st 50 or so. Take everyone's money for the full 500 and then sweep the 1st 50.

But that's real paranoid bizzare thinking on my part. Other then that I got nothing.

-Dave