...and that syntax applied to the simpler version:

While your code is quite revealing, your explanation leaves to be desired. You seem to be saying the following snippets are equivalent:

print "a", <<"END_OF_STR", "c";
b
END_OF_STR
[download]

print
   "a",
   <<"END_OF_STR",
   "c";
b
END_OF_STR
[download]

They're not.