That was dishonest. Fortunately, it probably didn't matter at all? Because there's not an evil spirit that condemns folks who eat beef products even by accident.
Evil spirits can operate sort of like pychosomatic illnesses though, right? If someone tells you that you just ate a parasite-infested human brain, are you not going to start freaking the fuck out every time you see a sun spot or have a weird dream? Feeding X to someone who worships X without their consent or knowledge is basically dooming them to a lifetime of fear.