The businessman was not home at the time of the attack Gurgaon: A mobile phone recovered from the scene of Thursday night’s encounter in Sushant Lok 1 has given police what investigators call one of the strongest pieces of evidence in the failed contract killing case — a video allegedly shot by the attackers as they opened fire on a businessman’s house.The footage, retrieved with help from ballistic and forensic experts, shows the shooters pointing their weapons at the house and firing indiscriminately, while one of the five accused records the attack on his phone. Investigators said the video was…