I suspect someone was just messing about... The "script" decoded as:
PUSHDATA(1)[51]... So it pushes 1 byte onto the stack... And that byte is [51]
[51] resolves to OP_TRUE.
So, it's an "Anyone-Can-Spend" output:
Anyone-Can-Spend Outputs
Conversely a transaction can be made spendable by anyone at all:
scriptPubKey: (empty)
scriptSig: OP_TRUE
With some software changes such transactions can be used as a way to donate funds to miners in addition to transaction fees: any miner who mines such a transaction can also include an additional one after it sending the funds to an address they control. This mechanism may be used in the future for fidelity bonds to sacrifice funds in a provable way.
Anyone-Can-Spend outputs are currently considered non-standard, and are not relayed on the P2P network.