Originally Posted By: morphememedley
I have to decide whether or not the irony is intentional.

It would depend partly on whether what the person didn't know was a grammatical fact and partly on whether the speaker had the emphatic multiple negative as part of their native dialect. In this partcular case, considering zmjezhd's status as a linguist of some note I would say that the irony was unquestionably intentional.

A loanword is a word that is taken unchanged from another language, e.g., schadenfreude from the German.