Is the US releasing Guantanamo detainees with implanted tracking devices?

Was it a coincidence that a senior Taliban commander, well after having been captured by US forces, detained at Camp X-Ray in Guantanamo, and allowed to return to Afghanistan, would suddenly be gunned down in a remote Afghan village while plotting to attack the government?

American troops captured Maulvi Abdul Ghaffar early in the war and shipped him to the US base in Cuba where he was milked of any intelligence he might provide. Within months, the Americans allowed him to go back to Afghanistan.

Why?

Could his release have been an intelligence operation itself? Could American intelligence officers have embedded a tracking device in the Taliban commander's body, unbeknown to him, permitting him to reunite with his terrorist network?

US intelligence could have tracked his every move by satellite. He might have betrayed, unwittingly, all his comrades: their locations, their movements, the structures of their networks - everything needed for the US and its Afghan allies to watch the Taliban's clandestine operations, and then to finish him off when he was no longer of value.

How many other former Guantanamo detainees might be released with tracking devices embedded in them?

If the US is implanting these systems, it would show a new boldness in fighting the terrorists. If it hasn't been implanting them, it should start right away.