Late to the thread SilentHill. First, don't blame yourself. You did everything you could. We've all been there with different outcomes. Shayna my BP is an albino spider and I lucked out, as she has no noticeable neurological issues, and will be 8 in a couple of months, but I don't know if I'd take the risk again. I was unaware of Spider issues when I got her.
Secondly, learn and move on. Beating yourself up doesn't help. You are a great Snarent and I wouldn't let this make you doubt yourself or your abilities or love for these animals.
I am really sorry this happened and my thoughts are with you, 67temp, and the little one lost.