Bootcamps are a red flag for you? What? Do you have any rationale for that? Makes zero sense to me. If someone has done a bootcamp, that's a big plus. Online college is neutral.
The rest I agree with.
If this person says that they've been coding for years, then that puts them at a way higher level than a recent bootcamp grad.
Instead of doing a bootcamp, spend a week or two building simple apps in whatever category you want to work in. If you want to be a web dev, a little node.js backend with a react frontend perhaps, or similar with Django or Rails.
Plonk it on your github, make sure you put on your resume that you're a junior that's been coding for years but never put anything in production, and you'll definitely be ahead of the bootcamp grads in my book.
Not everyone goes there to get technical skills, there are people going there for soft skills (practicing working on assignments, especially group assignments, etc.) and networking (at least some bootcamps advertise they have some relationship with recruiting agencies).