How to handle an angle-shoot in a home game.

[Toronexti]

I was playing in a 1/2 Home game last week and the following hand occured:

Board is A [img]/images/graemlins/diamond.gif[/img] 8 [img]/images/graemlins/diamond.gif[/img] 5 [img]/images/graemlins/heart.gif[/img] 3 [img]/images/graemlins/heart.gif[/img] k [img]/images/graemlins/heart.gif[/img]

On the river the player goes All-in and I call with AQo (taking like 1-2 minutes on the call). The player calls out flush, I wait to see his cards then he says "you got me, good call" and flips over 98o. I flip over my AQ and scoop the pot. Now I don't know anyone at this game whereas the AI player was a regular and knew most of the people. How should I handle this obvious angle-shot?