Any electronic trading system is capable of experiencing severe errors that have nothing to do with HFT; some of the most common examples involve manually keyin

Any electronic trading system is capable of experiencing severe errors that have nothing to do with HFT; some of the most common examples involve manually keying an incorrect price or size for an outgoing order. The sort of safety mechanisms implemented by the exchange (which shouldn't permit errors by member firms from damaging the market) to prevent these sort of problems are similar to the sort of mechanisms that can prevent crashes from faulty automatic trading programs.