I agree, but the timing is different to what you think. It wasn't 10 days after the BI article, it was a few weeks. But it took just a day for the agent to reply and another 10 days to have signed RW and be completing the proposal for publishers....some clarity below:
The editor and author of the 2025 piece says "A few weeks later" he gets an email from RW about some story of how the article had inspired a homeless man she bumped into on the SWCP near her house. The editor goes on to say:
Raynor also told me that she’d put her plans to self-publish on hold. “I had given up hope of getting an agent or publisher but randomly approached an agent 10 days ago, mentioning the Big Issue article (thought I’d give it one last go) and she came back to me within the day. Just completing the proposal to be sent out to publishers, so fingers crossed. Don’t think she’d have considered it if it hadn’t been for your article, so thanks again.”
So she found an agent a few weeks after the BI article published on 10 July 2017 and it took just a single day for her agent to reply to her pitch. And then by 10 days later she and the agent are completing the proposal for publishers (so she must also be signed). Then in March 2018 TSP is published. Quite a remarkable turnaround (for a first time author) given the amount of time and work that's usually required to publish a memoir/non-fiction book. I suppose it's plausible but it does seem incredibly quick.