I think the answer here is fairly simple - the key feature of technical debt is that its something we incur by choice.
We choose to make architectural, design or implementation decisions that we expect will cause us issues later in order to achieve specific objectives sooner.
A bug is not something we choose to have in our code - so de-facto its not technical debt.
Of course one can make all kinds of interesting (and possibly valid) arguments about choices made post discovery but fundamentally (and particularly in the context of the question) no, bugs are not technical debt - sounds more like abuse of buzzword bingo to me.