,Ok, if in the future some 300lb agressive person ( again we have no idea if he was aggressive or not, thats the million dollar question) is coming your way to pound the snot out of you. Please refrain from defending yourself and wait for backup.
As you say, we have no idea if he was aggressive or not. Since this is not a screenplay, I find the cop's story extremely difficult to swallow, though truth as they say is stranger than fiction.