In a legal sense the tax is being paid by the non-resident, so in the non-resident's home country the non-resident will typically get a tax credit for the Canadian withholding tax that has applied.
But your question points to an important aspect of this. In economic terms, although these taxes are imposed legally on the non-resident, with the collection being the responsibility of the Canadian payer, in the real world of many business transactions the non-resident will say, “I'm not interested in bearing that cost, so you the Canadian will have to pay me an amount that is increased to reflect the fact that the tax liability will exist.” So in practical terms you're right. Very often it is the Canadian payer who ends up on the hook for that tax.