It's easy to screw up. That's why cast iron is a bit better than running non-stick. You can get a hell of a lot more heat retention. It's a much tougher with a thinner steak because that immediate threshold of jumping from medium rare to medium to well done is pretty quick, and then you have to account for carry over temp when resting.
It looked good though, and hopefully it was still tasty. Practice makes perfect. Got a big side of beef try other cuts. I'll have to dredge up a good video or something. I don't do pan sear very often because I like my current gas grill or the slow and sear on my Weber kettle. I normally do the reverse your technique and make certain I've got thicker steaks. If I have a nice 2-in steak bone in, to me that's the easiest and most perfect cut to cook with the least amount of potential to screw it up as long as you monitor your temps. Other cuts and specifically their cuts can become much more challenging, and at that point it's all about super hot temps and doing it hard and fast.
But for doing it for a down and dirty steak without access to a grill cast iron still the way to go.