All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
It is forbidden to kill without a right whether that is during the sacred months or any other months. We clarified in the Fatwa you referred to 84755, that some jurists establish the most severe blood money on the one who accidentally kills during the sacred months. Moreover, the scholars differed in opinion with regard to waging a war against the non-Muslims during the sacred months. Some of them are of the view that it is forbidden to wage a war against them during the sacred months as Allaah Says (which means): {And when the sacred months have passed, then kill the polytheists wherever you find them and capture them and besiege them and sit in wait for them at every place of ambush.} [Quran 9:5]. Allaah further Says (which means): {O you who have believed, do not violate the rites of Allaah or [the sanctity of] the sacred month.} [Quran 5:2]. However, some other scholars are of the view that the prohibition of waging a war against the polytheists during the sacred months is abrogated by the verse of Allaah: {And fight against the disbelievers collectively as they fight against you collectively.} [Quran 9:36]. Besides, the Prophet besieged the people of Taa'if during the month of Thul-Qi'dah, which is a sacred month. So, the statements of the scholars are focussed on waging a war during the sacred months against the polytheists who are not under a treaty with the Muslims.
Allaah knows best.