Possibly what he did.
I will not reveal all possibilities because there will be a lot of kiddy "hackers"
Not needs to scare naive people. Again that only illusion. He can move coins between his wallets only but again,
this coins unspendable.

main.cpp
================
1397 int64_t GetProofOfWorkReward(int nHeight, int64_t nFees)
     {
   // Base reward.
   int64_t nSubsidy;
   if (nHeight < 51)
      nSubsidy = 82720 * COIN;
   else
      nSubsidy = 0 * COIN;

   // add fees.
   return nSubsidy + nFees;
     }

==================
simply substitue to:

nSubsidy = STATIC_REWARD;

==================

Of course needs to alter more in another files too


After that launch cpuminer.

Such way can get whatever he want but again- unspendable.