Assuming that the incident involved ice crystal particles in the vicinity of Cbs, then a lesson to be learnt is that these conditions are difficult to detect, and particularly that the ‘ice’ may not be detected by WXR.
With good WXR management the storm centre can be detected; however the ice threat conditions can exist some distance from the Cb core, particularly downwind of the storm and in/under the anvil, and thus a large deviation may be required.
Crews need knowledge of the threat, and appropriate judgement in avoiding these situations.
Also, assuming that at least one pitot probe was to the latest standard, then another lesson is that faults due to ice blockage can still occur, and possibly with modified probes if the conditions are severe enough. The alleviations are avoidance, less chance of simultaneous failure, and shorter duration if the storm is given a wide margin –
Airbus 20nm upwind .
Also see
http://www.boeing.com/commercial/aer..._article05.pdf