Using Covid to scare public - Matt Hancock’s leaked WhatsApp messages

Journalist Isabel Oakeshott leaked 100,000 of the former health secretary, Matt Hancock's WhatsApp messages to The Daily Telegraph, which exposed to the UK public the allegedly scandalous conduct of the government during the pandemic. For example, they reveal that Hancock wanted to 'scare the pants off everyone' to get the public to comply with COVID lockdown rules. But since Hancock trusted Oakeshott with these messages, did she breach journalistic ethics by compromising her source?