Shear Dynamics

My mind was just blown. This gentleman comes to our salon every few months and helps us with Shear sharpening, and he did a great job on mine last time. So he comes in today and I hand him my shears to sharpen and he says «oh man I bet that guy John did these”(he’s always bad mouthing other sharpeners). I was like oh no, you helped me last time. I guess he thought I was saying he messed up my shears (?) And said «I know my work and I didn’t do this» and refused to sharpen them for me. My whole salon heard and thought it was very weird, and said he gave them «a warning/​last chance» that if they had someone else do their shears he won’t anymore. Wtf. I’m all about quality control, and I mean for the most part I can go inside a haircut and see if it’s my work, but couldn’t anything he saw be left over from the previous «botched job»? I just really don’t understand why he turned away my business.