RED JOHN WOULD HAVE....

McAllister is NOT Red John.

When Patrick Jane finally caught and subdued him:

Red John would have been happy that Jane finally caught him.
Red John would have wanted him to KNOW, to UNDERSTAND, that he was Red John.
Red John would have mocked him and taunted him.
Red John would have laughed maniacally.
Red John would have said all he could to hurt him as much as possible. 
Red John would have expired with a smile on his face... A big, Red smile.