The 70-year-old actor received the best actor National award for the Sanjay Leela Bhansali directed film about a blind and deaf girl and her relationship with her teacher, played by Bachchan.
"For the 'River to River' festival in Florence recently, the choice of the opening film was 'Black'. I sat through it, and at every fault that I discovered in my work, I looked about to see if those that saw it with me saw it too ! And for some reason, when you discover that they did not, it sends a momentary pleasure, momentary," Bachchan posted on his blog. "The error that you notice remains, and bothers but alas nothing can be done with it.
I made a horrible error on the dining table scene in 'Black' and it haunts me till today," he added. 'Black' won the National Film Award for Best Feature Film in Hindi and eleven Filmfare Awards.
Bachchan himself did not point out the error but asked his fans to point out the mistake in a scene from the film, which also starred Rani Mukerji. "Though I am certain if asked none of you would be able to find out. Would you?
Let us test your judgement ! It is the dining table scene, when the younger sister to Rani, announces her engagement, and she gets up to give her speech and then Rani's letter to her elder sister is read by Mr Sahay (me). "What was the wrong that you noticed in my performance there? Love luck and happy viewing of 'Black' again for the fault finding," Bachchan wrote.