i don't think there is a mistake of amit ji . He had tried to escape himself and he has given only 9 digits . it is the audience who had put lat digit according to their assumption.
I dont think this type of cases are new as previously the same thing happened to Aamir khan. People noted the number which he wrote on his body in the movie Gajini. They used to call to the numbers for communicating with Aamir. The similar thing happened again but here Big B told some number which have 9 digit with the intention that people will understand it is wrong number. But still people are just crazy and added some number with the intention to call him.
