Why Is a Successful Flash Loan Attack Considered a Single, Complex Transaction?

It is a single transaction because the entire sequence of operations is bundled into one atomic unit for execution on the blockchain. It is complex because it involves orchestrating multiple contract interactions ▴ the loan contract, the DEX, and the target vulnerable contract ▴ in a precise order to achieve the manipulation and profit before the repayment check.

The entire sequence is pre-calculated and submitted as a single, highly optimized smart contract call.