If you see someone cutting bacon with a knife and then use that knife to cut your sandwich is that OK or do you need to AYLOR first?
You may be oversimplifying kashrus.
Here let me explain the way you can understand, think politics, it's simple Trump is a racist, Ocare built the country, all R's are bigots, and all food seen by a goy isn't kosher.
Well here's the secret, it's all BS, what you think in your own mind, but not with the understanding of those who know facts, you simple is just stupid.