Metal detectors are mentioned in the article; the survey they sent out: "enquired about staff awareness of implantable cardiac defibrillators and whether a hand-held metal detector might be useful in identifying pacemakers in mortuaries."

And again, later on in the article:

"54% believe that a hand-held metal detector might help identify pacemakers and other implantable devices that could explode"

Again, pretty expensive to equip every single crematorium around the world with metal detectors.

The lowest price I saw on Amazon was $18.

They're dead. Why not just cut them open and check?

Risk of infection; risk of scalpel accidents.

Then rock-paper-scissors for who has to take it out?