You seem very hung up on this one student being "harassed out" (whatever that means) of a school in Poland. I would think that it might be far more prudent to be concerned if there was a pattern of such activity in a school, rather than one person who left.
This was one person, correct? Bear in mind that there are some people who just cannot handle medical school academically, others who have serious problems in social interactions, and still others who do not have the discipline required to get through. While I am not privy to the details about this person leaving one school in Poland, and I think that some sympathy is likely in order, I also would hesitate to paint the entire institution (or country) because of it.
Finally, the differences between Eastern Europe and Ireland are vast, both culturally and academically. In fact, "vast" is a significant understatement. I would recommend that anyone choosing between these two options select Ireland without hesitation, assuming they can handle the difference in costs.
"When I haven't any blue... I use red."