That was my initial thought. I thought that maybe my back just wasn't ready for higher weights, but I wonder why my back felt great with the double overhand 195# for 1 rep and just completely fell apart for the first rep in the 225# mixed grip. It's a mystery. Also, I wonder why my back actually cracked instead of just tearing, etc.
I'm wondering whether this injury has something to do with my former injury. I'd think that if it did, my back would be in A LOT of pain.
Anyways, as of now, I'm considering employing some Steady State Programming for the DL for at least 2-3 months (i.e., DL 2-3 times/week 185# for a month and then 195# for a month, etc.). I'm thinking this will consolidate any potential weaknesses in my lower back-muscle, ligament, and tendon.
If I didn't have a prior injury, I'd probably just go right back into it once I feel strong enough, but I am really tentative about my lower back now.