Gen Urobuchi scripted this episode to be 45 minutes long, but producers had him cut it down to a run time of 25 minutes.
This episode is reportedly a favorite of Ume Aoki who has been said to have cried while watching it.
The manual Homura is reading from on bomb making is tittled Hara Hara Tokei, published in March 1974 by a far-left terrorist organization. Incidentally, the manual explains with illustrations that "Anyone with a middle-school level knowledge of chemistry can do it".
The building from which Homura steals weapons in Timeline 3 has a banner that can translate to "industrial enterprise", and with one Kanji character can be read as "Shafuto", the Japanese pronunciation of "Shaft".