But random people are free to make whatever conclusions about him that they want, with as little or as much evidence as they personally require to render their judgement. You don’t get to tell other people how they should form their opinions.
It isn’t fair, but there is no other way for the world to work. Everyone has their own criteria for judging people... we can put legal requirements on some things (like what criteria you can use to determine if you hire someone, or rent them an apartment, or let them into your store), but people are free to dislike someone for whatever reason they want.