[SWHouston]

Weather mandatory or not, when someone Microchips an Animal, that IS a record of ownership. Who else would legitimately do that ? Now, IF that owner was careless enough not to document a change of ownership or control, and, that animal caused harm/death, northing's changed.

That owner is responsible, regardless of who/how he delegated control of that Animal to another. And, I'm sure that any shaky paperwork concerning responsibility would firm up considerably, should a hefty Fine or other punitive action be taken toward the owner of Record.