I see it as dishonest and exploitative...
I find it faintly absurd to label all those who took advantage of this as nauseating criminals and compare us to looters.
Halfords have my name and address so they know exactly who I am, what I bought and what price I paid for it.
I offered to buy some stuff from their website and they chose to sell it to me.
They made a mistake in offering a bigger discount than they had intended to, but CHOSE to fulfil the order anyway.
The idea that they couldn't do anything about this this because "automated systems" had fulfilled the order is ridiculous.
It would have been a matter of 5 minutes work for them to run a query against their database to identify all orders placed in the affected time period which had used the offending discount code and stop them if they wanted to.
You have the warm inner glow of satisfaction that comes from knowing your moral standards are far higher than the rest of us thieving scum.
I however have have some bargain priced gear cables and bar tape and that feels pretty good to me.
I wont be losing any sleep over my reprehensible behaviour...