In which case we need more information.
What was the nature of the crucial help. ("tell me about judge X" vs "tell me how to win this case".)
For some reason I am not so eager to accept any information offered by a homosexual advocate lawyer when it comes to a purported conservative judicial nominee.
"Walter A. Smith, then head of the pro bono department at Roberts’ law firm, Hogan & Hartson, asked for Roberts’ help on the case and he agreed immediately. "It’s illustrative of his open-mindedness, his fair-mindedness,” said Smith. "He did a brilliant job.”
-Roberts did not select the case.
-Roberts' firm performed the pro bono work
-Roberts assistance was requested by the head of the dept of the firm.
Being put in that position may have been difficult if he is anti-gay, and not so difficult if he is for gay rights.
He may have felt he needed to accomodate his firm in spite of his personal feelings. He wasn't given a choice which side of the case he wanted to work on.
Or, he secretly believes in gay rights and felt great satisfaction in helping their cause.
I do not think either conclusion may be drawn based on what we know about it right now.