Earlier quoted context omitted.
There would be more social opprobrium to save the pet, and the grief would undoubtedly be greater if the pet died instead. If nobody was looking, I think most would save their pet. Unknown unrelated people simply aren't very important. Wars would be impossible if it were otherwise.
Interesting. Do you ever test your hypotheses? Here is some evidence regarding your "most" claim. https://www.google.com/amp/s/www.psychologytoday.com/us/blog...
Now, ask yourself how many would save their own dog if they weren't being asked or observed (and implicitly judged)?
I consider the link fairly strong evidence for my claim.