Take a look at flight routing! Is this a mistake? Any ideas?
Yes, a problem with the handling of the EGLL flight, which is international.
Thank you, as I did not think an 320 could go non-stop transatlantic! An A310 could, but not a 320!
The A320 does have the range to go transatlantic. It could fly Bangor/Goose Bay/Gander to Iceland/Ireland/United Kingdom with no problem. I’m not sure if it would be able to do this with a full payload, though.
Now, is it ETOPS (Extended Twin Engine Operations*) certifed? That’s another story. Right off hand, I can’t thank of any operator using the A320 on flights that would require ETOPS certification.
*Also known as “Engines Turning or Pax Swimming”
They have to be delivered from Airbus somehow, they don’t just show up in the US. 
Just off the top of my head, I can think of PrivatAir that flies the A319 from Germany to EWR, but this is not the standard A319, and certainly has much higher range than a normal A320.
Delivery flights don’t count. Besides, they bundle up a couple of A320’s and place them inside a 747F or AN-225 when they are sent stateside from Europe. 
Bulk aircraft shopping, like going to Costco for A320’s.
Speaking of delivery flights and overseas travel by smaller planes, here’s an interesting picture: