Because it was being reported by many accounts in Twitter even when the encounter was going on. That's why Indian OSINT's were leaking reports that Contact has been established again with Colonel Sharma and that they have been rescued to counter this narrative. However I think this is incorrect because they would have simply
blown off the building using IED but they did not because the dead bodies of Colonel Sharma and others had not been recovered (@arkos). There's just no other way to explain it otherwise in my opinion. It would be difficult to find source now but I will try to find it.