I liked this one.
However, I'm not clear on why the hit was called off.
Well, I've been thinking about this one a bit actually.
Assuming that Blaque is a capsuleer (or has otherwise taken advantage of softscan technology), then yes, the shooting would not permanently end him, merely put him a few weeks out of the loop at best and annoy him at worst. Whichever it is, it's a sure bet it would send a serious and worrying message to the Federation - the State would be saying "We can deposit agents carrying significant weaponry into your capital cities and assassinate your to people." That's a scary concept, even if it might not actually even be that hard on Blaque himsel.
However, when the possibility that Blaque wields significant influence in CONCORD - enough to more or less singlehandedly lead the charge to push a major bill through - one must also consider that even if merely inconvenienced, Blaque is likely to be seriously pissed by any assassinations, and might use his not-insignificant influence at CONCORD to squeeze the State further. Hence, figuring out how to deal with that takes precedence over immediately killing Blaque.