Ilyas Kashmiri's big mistake

How was it that Ilyas Kashmiri, the much-feared commander of al-Qaeda's 313 Brigade - so-named after the 313 companions that stood at the Prophet's side at the Battle of Badr - came to be killed, along with seven others in an orchard south of Wana in South Waziristan last week (see below)?
According to some reports, Kashmiri was discussing what al-Qaeda and its allies should do in the event of a Pakistani incursion into neighbouring North Waziristan. Pakistan's military has been under American pressure for months to launch attacks against the notorious Haqqani network and its supporters in North Waziristan, from where they launch attacks on Coalition forces in Afghanistan. Significant elements of the Tehreek-e-Taliban Pakistan from the Mahsud tribe who were formerly based in South Waziristan are also sheltering there, ever since they were chased out of their traditional tribal lands in a 2009 army offensive.
Kashmiri had only been in the district a few hours when he was killed in a targeted drone strike. Hardly surprising really; his very presence in South Waziristan was a threat to a 2007 peace agreement between the Ahmadzai Wazirs and the government under which the tribe agreed not to attack Pakistani forces or to allow foreign militants into their district. The Waziris had previously risen up against the Arabs and many Uzbeks from the Islamic Movement of Uzbekistan who had settled amongst them and who had become notorious for their cruelty. More than 200 Uzbeks were killed by the Waziris and the survivors were forced north, where they were given shelter by other Pashtun tribes.
As recently as March this year the nine clans of the Ahmadzai Waziris agreed to stick to the terms of the 2007 treaty, although the local district officers were pushing for it to be made tougher on the tribes.
So when Ilyas Kashmiri, a former Pakistani army officer who was reknowned for his brutality and who was certainly involved in serious attacks on the Pakistani armed forces - including the recent attack on the PNS Mehran naval base - arrived in the district, trouble was likely to follow.
Kashmiri was staying at the home of a tribesman known to be a supporter of Maulvi Nazir, an Ahmadzai Wazir and leader of the local chapter of the Tehreek-e-Taliban. Nazir had also signed the 2007 peace deal, but is known to be sympathetic to both al-Qaeda and the TTP.
However, other tribesmen in the area are unlikely to have taken such a sympathetic attitude towards Kashmiri, correctly realising that his presence would only bring further trouble to the area, particularly if he was the part of an advance guard of Punjabis and foreign fighters fleeing an army offensive further north. It would not have been long before someone reported his location to the military authorities. And they in turn, anxious to provide proof to the Americans that they are serious about fighting terrorism, and also determined to settle scores with a perceived turncoat, tipped off the CIA.