In the above video, Ghamidi sahib explains how imam shafi differs from others when tasmiyya is not being performed, but reading this it seems he has the same opinion as others that it will be lawful only when it happens by mistake
“As far as Imam Shafi’i (Allah have mercy on him) is concerned, it is usually related from him that the animal will be lawful to consume even when one does not pronounce the name of Allah intentionally, and that to pronounce the name of Allah is merely a Sunnah.
However, the great contemporary jurist, Shaykh Mufti Taqi Usmani (may Allah preserve him) discusses the viewpoint of Imam Shafi’i (Allah have mercy on him) in his Arabic treatise “Ahkam al-Dhaba’ih” concluding that this is only when it occurs infrequently. If a habit is made of not pronouncing the name of Allah due to negligence and taking the matter lightly, the animal would not be lawful according to the Shafi’i school also.
Shaykh Taqi Usmani (may Allah preserve him) states:
“It appears by looking into the book “al-Umm” of Imam Shafi’i that he did not explicitly mention the lawfulness of the animal on which the name of Allah is not pronounced, rather he only stated that the animal on which the name of Allah was not pronounced forgetfully would be lawful (halal). The text of Imam Shafi’i (Allah have mercy on him) is as follows:
“When a Muslim sends his (hunting) dog or bird, both of which are trained (to hunt), I would prefer that he pronounces the name of Allah. If he did not pronounce the name of Allah forgetfully, and the animal was hunted, then it would be Halal to consume from it….” (Kitab al-Umm, 2/227)
Further along, Imam Shafi’i (Allah have mercy on him) clearly states that the one who does not pronounce the name of Allah by taking the matter lightly, then the animal slaughtered by him would not be lawful. He states:
“If a Muslim forgets to pronounce the name of Allah Most High, the slaughtered animal is Halal to consume. However, if he did not pronounce the name of Allah by taking the matter lightly (istikhfafan), then the slaughtered animal will not be lawful to consume.” (al-Umm, 2/131, Bab Zaba’ih ahl al-Kitab)
These texts of Imam Shafi’i quite clearly illustrate that the Shafi’i school does not give a general permissibility of consuming from animals on which the name of Allah was not pronounced intentionally, rather, the slaughtered animal will be unlawful (haram) in the Shafi’i Madhhab also if the name of Allah (tasmiyah) was not pronounced due to being negligent or taking the matter casually and lightly, and that one make this a habit.”