The Germans and Austrians and the other Gauls have not always gotten along well with the Irish - and during Freud's time, there was still a very public bad attitude towards the Irish. Of course, me Irish ancestors did nothing to encourage this attitude with our readiness (eagerness) to fight at the drop of a hat. Faith, we'll even fight to make ya drop yer hat, begorrah!
In actuality, any difficulty Freud might have had with Irishmen would likely have been due to cultural differences. Both his folks and Irish folks are very strongminded - stubborn, even - and quite resistant to such things as attempts to analyze us. The other side of my family - German - is just as highfalutin' as the Mick side. And when we get together, look out! Tha' will have yer hands full, fer sure!