gavin said luke had to test bip17 on the real network because he wrote a stealing bot on testnet
so those transactions should already be somewhere out there in the real blockchain
(and you can steal luke's money if you find them
No, Luke didn't have to test on the real network.
He tested on the real network before he was aware of the stealing bot, in fact. He tested on the real network because he controls the content of the blocks of 400GH/s. He tested on the real network because he could.
When the stealing bot was noticed and was causing Luke some trouble with continued testing I mined some 40ish blocks to reorganize testnet to undo the stealing bot so Luke could continue his testing there. (something that I couldn't do on the real network, which is part of the reason testnet is so much better for testing)