The ball didn't help him time his shots, help his hand-eye coordination and placement etc. All of which Gilchrist displayed. He was out of form after the 2005 Ashes, but still hit the odd great innings. Tendulkar has been out of form for a long time but hits the occasional good innings. Lets not start a double standard.
Anybody who saw that innings saw Gilchrist in-form because he was hitting the ball cleanly. That ball doesn't stop him from mistiming balls etc.