Answered by Shaykh Rami Nsour
Question: Assalamu Alaykum,
1. The brother who was slaughtering my goat did not realize that the blade was not sharp enough, until after the blade had already cut into the goat, so he continued with it. Does this make the meat of this animal impermissible?
2. Also, does the one slaughtering have to mention the name of Allah, or can a Christian slaughter the animal, while a Muslim standing with him mentions the name of Allah instead?
Answer: Wa alaykum as salam wa rahmatullah,
1. As long as the blade could cut through the skin, it will be permissible to eat. It is highly encouraged to have the blade be sharp, as it will prevent undue suffering of the animal.
2. For a Muslim, it is an obligation to mention the Name of Allah. For a person of the Book (Ahlul Kitab), it is not an obligation to mention the Name of Allah. There is no need to have a Muslim stand by and say it.
And Allah knows best.
Rami
Source: http://seekershub.org/ans-blog/2015/10/31/is-it-permissible-to-eat-the-meat-of-an-animal-slaughtered-by-a-blade-not-very-sharp-maliki/