Define "uses". There's certainly structural similarities:

https://github.com/john-connor/vanillacoin/blob/master/src/key.cpp vs
https://github.com/bitcoin/bitcoin/blob/0.9/src/key.cpp#L16

https://github.com/john-connor/vanillacoin/blob/master/src/utility.cpp vs https://github.com/bitcoin/bitcoin/blob/87f37e259d6deb52ee464edde7aece687eea97a5/src/main.cpp#L1094

https://github.com/john-connor/vanillacoin/blob/master/src/block.cpp#L301 vs https://github.com/bitcoin/bitcoin/blob/0.9/src/miner.cpp#L115

It's certainly no cleanroom implementation. IANAL, couldn't advise on whether that counts as use, though.