"The CIA used a futuristic new tool called “Ghost Murmur” to find and rescue the second American airman who was shot down in southern Iran, The Post has learned. The secret technology uses long-range quantum magnetometry to find the electromagnetic signal of a human heartbeat"

Note, I agree that it was probably some novel beacon technology. Just answering your question about why people are debating whether it was a device that could detect a human heartbeat from long range.