unexpected GetType() result for entity entry

You can get the original entity type of a proxy type by

ObjectContext.GetObjectType(entity.GetType())

This is a static method of ObjectContext, so you can readily use in in a DbContext environment.

If for some reason you need the actual entity as its original type you can use the pattern

var entity = entry.Entity as MyEntity;
if (entity != null)
{
    ...
}

This is slightly more efficient than

if (entry.Entity is MyEntity)
{
    var entity = (MyEntity)entry.Entity;
    ...
}

because the latter snippet casts the object twice.