As I think of it, credit (what got destroyed) and currency (what was used to create the credit) are interchangeable - $10 of credit buys as many seedlings as $10 of currency, hence we think of them as one 'thing' - I might call 'money' the category including both, though I'm no expert in economics either and these might be nothing like the official jargon. But what does seem reliable is that destroying $4 of credit has the same effect on the price of apples as would destroying $4 of currency, though the latter is a more rare event.