I've been out of the laser game for a while and I can't tell you what to expect out of these, but looking at issue from what I've learned in my EE university classes and some quick googgling here is possibly a logical guess for shorter than normal life.
A. Your using the micro-boost driver, it has a ripple of 5% listed in the datasheet, and that is rather high compared to other drivers. Electronics don't like ripple very much, so that could be a contributing factor in the short life.
B.Prolong exposure to heat. No electronics like heat and assuming this was removed from a sled, this has had heat applied to it 3 times. Once to get soldered in the sled, once to get removed from the sled, and once to get soldered onto your laser. Were all those soldering esd safe and within the stated spec listed in the data sheet? Maybe, maybe not.
C.High current, despite the fact that people run these diodes way beyond their intend power all the time doesn't mean that it will work. These diodes are probably only designed for something like 200-250mA and they all work at that current, but the higher in current you go the fewer and fewer diodes can handle that amount.
Hope this provides you with some insight, maybe you knew this stuff, maybe you didn't, either way, killing a diode sucks!