Does this count as stealing?

I was at Walmart and the item I was looking for was marked as half off. So, I grabbed 2. Price I was expecting, double the product. I go to self checkout and the price is the normal price (no half off). I pretended to scan the second one and kept going. Walked out hoping nobody would ask to see my receipt (nobody did).
It could be said that I stole the second item and lied by pretending to scan it.
On the other hand, I paid the price that the store said I would pay. I held them to their word, and the system just may not have known about the sale.
I think I’m in the right, but what about yall?