A West Midlands Police spokesman said: "These are challenging times and our officers are adapting to the new legislation and guidance which has changed many times during the pandemic.
"Government law says that no person may, without reasonable excuse, enter or remain within a relevant place without wearing a face covering.
"We understand that these restrictions are difficult for everyone, but we must all follow the rules to overcome this pandemic."
It helps if you teach your officers what those rules actually are, rather than allowing them to make it up as they go along:
The 28-year-old said he told officers he had asthma and he was medically exempt but claimed one of them demanded his details and threatened to arrest him in a branch of Lidl in Birmingham.
Mr O'Hagan said he insisted he did not "need to disclose his medical history" but claimed he was eventually handcuffed in front of other shoppers and taken outside. "I'd forgotten my phone, my wallet, my inhaler and they kept going: 'You need to prove it, you need to prove it'."
He went on: "I explained - as per the Government website - you don't have to have a card on you and it was just a verbal thing you needed to say."
Mr O'Hagan said his partner returned home to collect his exemption cards and inhaler, but this was not enough to satisfy the police.
He added: "They took me out of handcuffs, de-arrested me and had a look at my records but said that, because my inhaler didn't have my name on it, they would still have to fine me."
We shouldn't be surprised, for one thing, WMP are the most dysfunctional farce in the country, and for another, the real reason for this dogged determination to pin something on the poor sod is because he had the temerity to argue.
Mr O'Hagan appealed the fine and the fixed penalty notice was quashed. He has now complained to the Independent Office for Police Conduct (IOPC), the force watchdog.
Will they take appropriate action? Probably not.
H/T: Suzanne Evans via Twitter