When the Army Chief (Vikram Gokhale) asks Colonel Abhay Singh (Manoj Bajpayee) whether he knows Gurinder Singh, Colonel inquires "Lt. Gen. Retired Gurinder Singh(?)" whereas the actual way of saying it (according to Indian Army Circular July 21, 2014) is Lt. Gen. Gurinder Singh Retired.
It is clear from the movie that Captain Maya Semwal (Pooja Chopra) is acting as the third-in-command of the covert unit after Major Jai Bakshi (Sidharth Malhotra). But there are two team members Lt. Col. Aubin Mathew (Maan Praveen Sirohi) as well as Lt. Col. Anees (uncredited actor) who are of higher rank. Normally one of them should be and will be the second-in-command after Col. Abhay Singh (Manoj Bajpayee), especially in a military organization. (Please check the award ceremony and shoulder badge of the team members.)
When Mukesh Kapoor (Aadil Hussain) watches the news feed at TV about the shoot out, in the caption it is written that "3 People shot dead at merchant square." But from the shoot out scene, it can been seen that only two were killed including the MI6 agent. And the news reader mentions only about the death of MI6 agent.
Colonel Abhay Singh and Major Jai Bakshi are shown as landing at Heathrow. But, this was actually Gatwick in real life! Scenes were shot next to a Heathrow express train to make audiences believe that they had actually landed at Heathrow.
In the coffee shop scene, Jai Dikshit's original identity is revealed to Sonia. However in the earlier scenes she hacks his laptop and credit card details which had Jai's actual information.