It’s not often that Ryanair’s famously outspoken boss Michael O’Leary meets his match, but that’s what happened last week – and the winner in this war of words, and actions – was the CAA’s chief executive, Andrew Haines.

Unlike O’Leary (pictured), the CAA is not normally known for its fighting talk. But Haines was unusually forthright in his condemnation of Ryanair’s apparent disregard for thousands of passengers whose flights Ryanair had cancelled due to “messing up” the rostering of pilots.

Ryanair first angered passengers by cancelling 40-50 flights a day in the six weeks to October 28 due to a pilot shortage. It then suspended another 34 routes this winter, eight of which are from the UK, which amounts to another 18,000 flights. In both cases, Ryanair reportedly failed to inform consumers of their rights around being reaccommodated on other carriers or to be refunded expenses.

Normally, Ryanair’s behaviour towards some of its customers goes unchecked. But this time, the CAA had had enough. It contacted Ryanair on September 18, warning the airline that it had misinformed passengers about their rights under EU261 consumer protection laws.

The CAA was further riled when O’Leary incorrectly claimed at a press conference that the airline was not obliged to reroute passengers on other carriers. O’Leary had claimed that Ryanair “could not afford their high fares”, an incredible statement even for the bullish boss, considering Ryanair’s profits after tax of £1.1 billion in 2016-17.

Haines proceeded to go on national radio to declare he was “furious” about Ryanair’s actions and that the CAA was taking enforcement action over the issue – with the deadline set for 5pm on September 29 for Ryanair to change its advice to customers.

Haines’ demands, believed to be unprecedented, included the issuing of a press release explaining how Ryanair would reroute passengers on other airlines and a commitment to help those who made choices “as a result of being misled by Ryanair”. Haines also demanded the reimbursement of out-of-pocket expenses incurred by passengers.

A game of brinkmanship ensued, with Ryanair finally changing its advice to customers less than one hour before the CAA’s deadline.

The new advice crucially states that passengers affected by the cancelled flights can use “agreed disruption partner airlines to their destination”. These airlines are: easyJet, Jet2.com, Vueling, CityJet, Aer Lingus, Norwegian and Eurowings.

Ryanair said it would “also reimburse any reasonable out-of-pocket expenses” for customers affected “subject to receiving an EU261 expense claim form from customers supported by original receipts”.

Haines described Ryanair as having “capitulated” and vowed that the CAA would “monitor this situation to ensure that passengers get what they are entitled to in practice”.

“Our job is to protect passengers’ rights and ensure that all airlines operating in the UK are compliant with important consumer laws,” he said. “Where we find that an airline is systematically flouting these rules, we will not hesitate to take action, as we have done with Ryanair.”

Meanwhile, O’Leary has been keeping an unusually low profile.