Can't say on BOI specifically, but it I have seen other banks in NI charging the beneficiary (c. £10) for recieving GBP transfers from ROI-and the sender would be charged a similar amount by their own bank (€12-€15 euro).
If it's a non-EU country, it wouldn't surprise me if the charges are higher.
If it's a seperate transaction, then it is likely to be BOI charge. If it is a reduction in the GBP equivalent (of the non-GBP amount) then it's not a BOI charge.
Normally there's a charge from both banks. You should receive a confirmation telling you the costs.
Some of the eastern European banks have very hefty charges.