It's hard to say really. Meat keeps well when cold, and the marination helps it keep too. I'd say as long as it's not moldy, it's probably safe. I mean for one thing, most bacteria is burned off in cooking anyways. Now I'm not saying you can eat meat no matter how old as long as it looks edible, but 5 days seems doable to me. With pork lion, the worst you'll get is diarrhea, which isn't that bad at all really. With almost any aged meat, there's almost nothing fatal you could get, so it's really a pretty small risk. Just to be safe, I'd say don't cook it any less than medium.