For whatever reason the pilot continued to Jersey. It may well have been the right decision, we don't know. Maybe he had good reason to continue the flight.
But, to "not notice" the damage is rubbish in my opinion. I am looking at the photo now, and there is no way a pilot with 4 pax onboard could not notice the damage. With over 50% of the port aeileron missing,a significant portion of the left wing off, and the un-aerodynamic properties of the damage, the fuel imbalance, it couldn't have been missed.
Maybe he hit one of those 20-lb Bustards, the birds they recently imported back from Russia to Salisbury, I don't know.
Now I'll wait for the report before continuing any speculation