SANHA and raibow chickens

ASalaamualaikum
I happen to speak to an ex-employee a while ago (He was the supervisor at Early bird Chickens) and hs not left the company after 16 years. I asked him to tell me as a Muslim brother whether or not the chickens were halaal bearing in mind he has no nig salary to lose. He told me that they were difinitely halaal and then I questioned him about the slaughterers affidavits, his response was that how did the slaughterers themselves ate the chickens. Now in all this time of hearing that there are problems and also relying on the taqwa of the slaughteres why did no one bring this up? If you have so much taqwa to expose SANHA then why eat the chickens yourself if what he is saying is true.
I just wanted to know why this was not brought up in this tug-o-war??

Jazak-Allah