Of course, any system can fail, this works both ways for the missile and the SAM.
I didn't make assumptions as to the performance, as known, of the system, that is based on data collated and contributed by senior members such as Oscar and Secur.
The base line lateral acceleration required for intercepting a terminal phase ballistic missile as calculated by the USN when testing the SM-2 was rounded off at 60g, an inbound which is hurtling at high hypersonic velocity (mach 7-8 plus) being intercepted with a mach 3.5 interceptor is well and doable, the problem is that were the inbound to "shift" with aid of attitude thrusters (easier on liquid fueled inbound) then the interceptor would require an immense amount of lat acceleration to reorient itself. The Barak-8 has been specifically designed, as evidenced by its design choices- of extremely high lateral acceleration (80g compared to the Aster's 12g, and mind you the Aster is seriously meant for TBM interception in concert with a proper L-band solid state VSR) at the cost of absolute velocity and slant range, for anti-AShM role.
Of course this doesn't mean that the CM400AKG is a dud, if a competent AAW system could render all munitions irrelevant then no one would opt for said munitions, even when one moves from the amateur notion of platform centric warfare to the actual prevalence of net centric warfare one realizes the summation of capabilities at hand and any form of comparison only lead to likelihoods in terms of probable or improbable and not possible or impossible. So, yes anything could come to pass in terms of possibility, its just very improbable that a hostile flight will first avoid detection from the deployed Okoeye AEW, then penetrate the BARCAP, get a clean shot and that the munitions will strike home. Furthermore, systems like the AKG are not new at all, the USSR had a bolt to bolt copy of said system (and I mean bolt to bolt, shape, size, range, speed, even warhead weight) in the early 70s and yet after successful operational deployment of the system they abandoned it in favor of sea skimming supersonic AShMs due to the advent of high performance interceptors, and mind you the USSR was the original patron of the strategy of deploying a massive number of AShMs (air launched by the bears, coastal and submarine) in order to execute a saturation strike against hostile CBGs and SAGs.