I've never had tuna that looked like escolar, assuming the comparison pictures in a Google image search are accurate:

https://www.google.com/search?q=escolar+vs+tuna&tbm=isch

Particularly this image:

http://3.bp.blogspot.com/_7tZTQT-lBpA/TJARkX5NXeI/AAAAAAAAAg...

If I received sushi or maki that claimed to be tuna but looked like a ghost I would send it back. Is the use of escolar as tuna a regional thing, or is some escolar a pink/red color?