You know, interaction with pirates is "life in it's purest form", just like primitives or animals for instance. Basically the guy with the bigger gun rules or something like that. It's -not- supposed to be fair. It's more like a "screw you and your anything" kind of interaction. So yeah, it's completely normal to expect the unexpected when dealing with pirate demands.
"If your heart is filled with faith, then you can't fear."