Plus how does it get to Paki without flying over India and getting hit on radar?
If it flew to the Maldives, picked up fuel and went north....maybe...but even that is a stretch.
The pilot of the shadowing airplane could just listen to traffic control center and copy a clearance given to a different airplane and follow a thousand feet below and slightly behind the legitimate craft.
It is possible that controllers could notice a skin track on the shadowing airplane but really could not do anything about it because it would be unidentified and would be gone before an interceptor could get there to check it out.
As long as it stayed 200 NM off coast of India, it would not be detected flying to Paki. Bothers me that Pakis have nukes ...
“Indian radar may have been turned off at night.”