@Star Wars This is all about information warfare.
You do not understand the most important aspect of counter insurgency warfare. Information Warfare.
When you perpetuate incorrect claims, the group/outfit they belong to will twist this narrative to mean that they could evade so many thousands of indian troops .... and reach that area in less than 24 hours. And they have a surge in volunteers/recruits.
Now, what actually transpired is this seems to be a case of fresh infiltration and some one somewhere messed up and is doing a serious cover of your a$$ in the process denying India a chance to pinpoint Pakistan for pushing in more people to foment trouble.
Tangdhar is located in a bowl, the heights are majorly dominated by Pakistan. It is limited in terms of ingress routes and the only way to ingress or egress from SAID LOCATION OF BSF INCIDENT is by crossing at minimum 8 tiers of security forces not to mention JKP and CAPFs in towns and cities/villages, an impossibility as it shall need failure at all levels.
Also, it can be a BAT action by PARA SF team on specific inputs allowing the ingress to occur by giving a false ingress route - entrapment.