Announced a losing hand but had the winner.

I was playing last night and had A7s, I put out a $50 bet on the river thinking I missed and he called. I announced I had only A high but I tabled my cards. Upon further review myself and the dealer saw I had an A high flush. The guy I was up against got really angry and said that he should’ve won since I announced I only had A high. He explained that on a “bigger table” he’d be the winner. The chips did get pushed my way but he got really frustrated like me and the dealer were in the wrong. I did explain that I tabled my cards for the dealer to see and we all saw that I actually had the better hand despite me not realizing.