South Africa's relay team never made it to the third section of the 4×400 in the opening heat after Ofentse Mogawane crashed, leaving Pistorius waiting with his hand outstretched for a baton that never came.
When he realised his Olympics were over, Pistorius raised his hands to his head, and waved his arms down in frustration. Since the South Africans had already won silver at the world championships last year, the "Blade Runner" knew his team had a good chance of mounting the Olympic medal podium after Friday's final.
Mogawane and Kenya's Vincent Kiilu tangled heading into the home straight of the second leg of the relay and the South African runner crashed, holding his shoulder with pain.
Pistorius still held his hand out for several seconds, seemingly unclear about what happened, until it slowly dawned on him he would no longer run.
Together with anchor runner Willem De Beer, he tried to walk over to his injured teammate but track officials held them back. Pistorius was left to applaud Trinidad and Tobago, which won the heat, ahead of Britain.
"It's very disappointing, especially coming off second place in the world championships last year," said Pistorius, who runs on specially constructed carbon fibre blades.
"We're pretty gutted. We've been training as a group for the last five or six years."
Pistorius, who was followed here by his 89 year-old grandmother, who cared for him and his brother and sister after their mother died 10 years ago, said he hadn't seen what had taken place.
"I took my eyes off the screen when he rounded the bend so I didn't see what happened. I was just waiting for the baton," said Pistorius, who will return here for the Paralympics later this month.
"I don't know if he got spiked or caught up. He's a phenomenal athlete.
"I feel sorry for my team-mates. Things do happen in relays."
He admitted, however, that it was tough to see his adventure end in such an anti-climactic manner.
"It's so hard, especially with the crowd being so amazing and there being so much support back home," he said.
Pistorius (25) who had only learned on the eve of the relay he would be running in his preferred third leg spot, made history last Saturday when he made his Olympics debut in the individual 400m.
The South African, who had both his legs amputated below the knee before he was one, because of a congenital condition, had fought a long battle to be allowed to compete.
Pistorius competed in the Athens 2004 and Beijing 2008 Paralympics.
He was given the green light for the Olympics following studies that found his prosthetics give him no advantage over his able-bodied rivals. – Sapa-AP