As others have likely said, no one said anything initially because they just assumed you knew that playing one more hand entailed that your $500 stack was still in play despite being racked. The dude who asked you directly probably should have told you to put your rack back on the table from your lap, though.
It's best to not give a fat sh*t about what others think or say about you. In this spot I would just apologize and explain that you made the mistake because you are new to live poker and just bounce.
You're going to run into a lot of bitter jerks in this world and in this game specifically.
You'll look back on this situation a year from now and think it was funny. It's all good.
One of my very first live experiences, I won a large pot that had $100 bills in it. I didn't like the idea of bills on the table so I wanted to put them in my wallet... BUT, before I did, I asked the dealer, "Can I put these in my wallet." "NO," he said, "... but thanks for asking!
" He seemed genuinely pleased that I asked before I did it. lol