Perhaps the neighbor who called it in thought that if they approached the child themselves, they might be seen as a potential child molester.
I'd call security too. Not my monkey, not my circus.
Take off my uniform.
My partner spent several years in childcare, both at centers and as a nanny. We're out in public and she sees a crying child? She goes to it, talks to it, hugs it perhaps, reassures.
Me? Not a chance. For better or worse, societal conditioning is that that is something I as a male /do/ /not/ /do/. Because it's nefarious that I'd even want to.