I wouldn't have had any concerns at that, mechanics is a STEM subject. Lock picking is an engineering skill.
Learning to pick locks doesn't infer that you're going to commit a crime, you may be working on your career options. In just the same way that installing Kali Linux doesn't infer that you will be a black hat bad actor emulating Matthew Broderick's character in my favourite computer based movie. https://www.imdb.com/title/tt0086567/reference
There's a lot to learn about the intricacies of lock cores and the tools needed to pick them. https://www.youtube.com/channel/UCm9K6r ... igLoZOh6FQ is a good starting point.
https://www.youtube.com/watch?v=ANsipsS7IK8 shows that picking the lock may not be needed.
https://www.youtube.com/watch?v=z4lVylO7y5U shows a small knowledge of electronics can help security.
The most amusing thing is WM Police having discord on their list. Do you know of any hard-core 13+ gamer that doesn't use discord?
That WM Police item also goes to show that too many folks (especially folks in power) are too stupid about how computers and the internet work, starting at Boris and his cabinet and working down. Perhaps the clever folks at GCHQ should be offering "Computers and the Internet 101" for politicians and their ilk to help them avoid continuing to look like a proper bunch of plonkers.