Submited checkpoint not for yourself. A bug?

Hi. Please explain why this node submited checkpoint for other node?

Node signer: 0xddb833b9e0e3f2f521480e7bcb3e676e0737047d
Other node signer: 0x7b5000af8ab69fd59eb0d4f5762bff57c9c04385

It looks like a bug and I have much more examples where small nodes submited checkpoint for other node as well.

It’s intended behavior, checkpoints can be pushed by any entity to avoid possible blockage by a malicious or crashed validator.

Who in such case should receive compensation for proposed block: node that submited checkpoint or node reflected in DATA?

A node that proposed the checkpoint. Tx sender doesn’t receive any matic.