The jet you're talking about is owned by a private company, H211 LLC, that's owned by Page, Brin, Schmidt et al. It's not a subsidiary of Google, nor does it have any relationship with Google[0].
I was arguing "the Boston dynamics robot is not Google technology because darpa funded it" with "it is fair to describe it as Google technology because Google own the technology".
You can draw whatever conclusions you like about the fighter jet for all I care. But if you start saying things like "they bought a fighter jet but they don't own it because someone else paid for the design" then I'll argue about your reasoning.
Who funded it and when is irrelevant to whether it belongs to google.