The problem with these type of statistics is that they only show you a snap shot at one point in time.
The same report 5 years ago probably would have shown Ireland on top as the ISEQ was outperforming all the other stock exchanges and Irish managed funds had more Irish shares in their equity portfolio's. While that was fine in boom time, its hit those funds harder now the economy is going south.
I'm not defending investment managers or trustee's but any equity based investment carries risk and no one has a crystal ball to predict what will happen. The only thing they possibly could be accused of is having too many eggs in the one basket.