Journalists are stupid. The "how" is that it flew there.
The military wants to know the "why", not the "how".
Are you sure about that? According to the article/s it doesn’t have the radio range or the flight range to fly 1,200 kilometers.
It posed a threat to other air traffic, especially if it is poorly spotted by collision avoidance systems. Could have climbed easily to 18,000 service ceiling.
C-130 midair collision on approach to landing FOB Sharana resulted in loss of two engines and wing damage in 2011. Not an RC model by this result.