Apparently according to several media reports, the flight to Dublin was a surprise for a niece which could put what happened under a slightly different light
If true, and the trip was a surprise and therefore a last minute decision, that could be why planning was not quite as thorough as would normally be done...such as maybe not being quite so well organised in respect to weather en-route and so forth
Not just pilots have made quick, spur of the moment decisions that have not worked out well for a variety of reasons...maybe this is one such occasion and its ended tragically