What's interesting is when I booked the tickets, half way through the purchase journey I got a popup saying "Are you human?" with a reCAPTCHA to verify that I was human. They still tried to charge me £10 at the end for a "System Surcharge".
afaik airlines pay a surcharge to systems that have authoritative data on flights (GDS/Amadeus) iff their look/book ratio is too anomalous, which is exactly the kind of number scraping bots really play with
What they should do in these cases is to fallback to a captcha or something like that.