Is the questioner sinful for eating chicken over which the Tasmiyah (invoking God's name) was not certainly pronounced at the time of slaughter due due to overcrowding?

What is slaughtered by a Muslim is permissible to eat according to the majority of scholars, even if they did not pronounce the name of Allah due to forgetfulness. This is the well-known position in the Maliki madhhab (definition), and the view of Malik, Al-Thawri, Abu Hanifa, Ishaq, Ata, Tawus, Sa'id ibn al-Musayyab, Al-Hasan (definition), Abd al-Rahman ibn Abi Layla, Ja'far ibn Muhammad, and Rabi'a. They substantiate their view with the saying of Ibn Abbas: "There is no harm for one who forgets the تسمية (pronouncement of Allah's name)." And that the verse: "And do not eat of that upon which the Name of Allah has not been mentioned" {Al-An'am: 121} is interpreted as referring to what the تسمية was intentionally omitted from, as indicated by His saying: "and indeed, that is grave disobedience."