No.
Not if you are trying to analyse why Ireland didn't win the world cup and you are advancing bullshit reasons like "lack of belief" or "choking" or "some sort of jinx".
I'm not advancing "some sort of jinx" as a reason, but lack of belief and choking - absolutely.
Let's actually look at facts shall we, not "what ifs". Ireland played NZ in the QF - going into the match Ireland were ranked no1 in the world, NZ were ranked no4, and on the points used for ranking NZ were virtually as close in points to Fiji in 8th than they were to Ireland in first. So on paper Ireland were much stronger.
Add to that that Ireland had won three of their previous four matches against NZ (critically all in friendlies where all that was at stake were the bragging rights).
Add to that that the match was played in Paris, just a short hop from Ireland and on the other side of the world from NZ - so Ireland with close to home advantage.
Add to that that the match officials were from England and there has long been a suggestion that SH and NH officials interpret matters slightly differently so better to have a ref from your part of the world.
Add to that Ireland played a quarter of the match with a player advantage.
So all of these factors suggest that Ireland should have won. Yet they lost, and although in the end the match was quite close they were never in the lead at any point. Hard to argue that despite having the best possible chance to win a QF that they bottled it and they simply didn't have the self belief that they could beat NZ in a knockout match in the world cup. NZ on the other hand were supremely self confident that they could win despite being weaker on paper, playing much of the match a player down etc etc. They just wanted it more and had greater self belief.