Block chain can only track something (in this case money) from the time that it is applied. You can't trace money "using block chain" back to someone who did not apply it prior to transferring it.
A Faraday cage is shown being assembled by attaching plastic garden fencing painted silver to a metal pipe frame with plastic cable ties. Only metal fencing or welded mesh securely attached to the metal frame with metal fasteners would work.
When Aram is describing what the hacker could make the pacemaker do to the girl's heart, he is incorrect. He is describing what an ICD does, i.e. shock the heart if it stops. A pacemaker stabilises the hearts rhythm.
The entire resolution of the case is based on finding the laptop by using the remote diagnostic feature on it and to get an IP address and thus the location. However, the owner of that laptop is a prolific hacker who would know about this feature and would have disabled it for obvious reasons (the same is true for the webcam).