I just don't want this clown going to my management and saying "look at the ignorant questions this boob is asking - you should get rid of him
That is a genuine consideration, however there is the flip side to that.
What is the "management" like? When I was a manager, had someone come to me and "reported" such activity I'd have frowned on him more for being a grass (unless there was good reason and you are bad at some things - bad security approach in code etc).
So the flip side is to say to your "boss"
I know my job and am good at it, but the world changes, technology changes and by reading and asking I'm keeping up with the times.
The "other bloke" (who reported) cannot know everything, so where I ask professionals on a site to get the best practice possible so my code and approach is of a high standard, what does the other bloke do when he doesn't know how to do something? Just guess? Do some bad code and avoid anyone seeing them asking questions?
Also, if he never asks, as I do, how does he learn new standards and improved technologies? For example, in PHP with the version updates, they release new and/or improved libraries which need to be researched and learned in order to use them within the workplace. A prime example is over the last X years OOP in PHP has gone from being a clunky hack-like usage to being part of the core libraries.
There's always two ways to skin a cat. You seem confident, and is right you are asking pros on Stack to learn new things and check you're following best practices and industry standard methods.
Just relay that to your colleague and see what they say.
If all else fails and they report to your boss, just be confident and explain you know your job very well but everyone needs to remain up to date, and if the other bloke isn't then maybe he needs evaluating...
If you're really that bothered, and think your current account has been successfully identified, then make a new one where you give nothing away.
There are millions of users on SO, it would be laughable if someone suggested one was you without clear evidence.