Yes, nothing to stop them issuing a PCN - but it doesn't make it necessarily payable, of course, nor justified half the time. Neither is it 'illegal' to park in contravention of a traffic order. It's merely a civil charge because almost all Council s now operate 'decriminalised' parking. Not...
No such thing as 'illegal parking' with a Council PCN, except in a few places in the back of beyond where the odd Council still operates criminalised parking offences.
He wasn't 'illegally parked' because this isn't about a criminal offence, it's civil parking enforcement.
Not me, if that's what the OP was thinking (me and Westdene Seagull, because we help people appeal & win any PCN case?). There is nothing 'illegal' about getting a private or a Council...