Or they were a whitehat wanting your problems to be caught in testing.
I don't remember the address we used, though. Here's [1] a similar one, for "correct horse battery staple" -- the funds were moved (in the same block) from the address to a single-use address where they sat.
[1] https://live.blockcypher.com/btc-testnet/tx/835509e51ab9054e...
Bitcoin does not support embedding messages in addresses (and embedding messages in transactions is controversial as it will be stored in blockchain forever, so many block explorers do not render such messages to discourage it).
[1] https://testnet-faucet.mempool.co/