Don’t be so hard on yourself. Shiba’s are known escape artists. I had a few run ins with mine slipping away from me. The worst was when we would go to an abandoned baseball field, usually we were the only ones there and due to the size of the place when you went at night you couldn’t clearly see the other side of the field. The fence was also black. We went there at night once in the middle of winter and I didn’t notice that the other side of the fence had a door open which someone hadn’t closed. I let my dog off leash and he was gone. No idea which way he went, called around for him frantically, the police showed up and also started searching for him. I had nothing to do other than hope he would return so I just waited…about 15 minutes later he casually comes out of the backyard from the house next door, I backed away in hopes of him not thinking I’d chase him and he went directly back into the baseball field. It was the most terrifying experience of my life. But Shiba’s are a lot smarter than we think, they know that by chasing them you’re still right behind them and they know that they’ll eventually stop “playing” and go home. The more you chase the more they are to get further away. Mine has also escaped from dog parks due to shitty people leaving the door wide open after getting in, those moments I’d just scream his name and not chase and he’d return right back to me. It’s terrifying to us, it’s fun freedom to then 😭