[darkcha0s]

>But one day, a colleague spots Bob working on his project during work hours and informs his manager about this little stint

Bob's problem was using his work hours to work on his personal side projects. While there is some truth to this, generally companies don't go after you unless they have a reason. Every company I've been at (before founding my own), my employer (who, among others, was a big4) wouldn't have blinked an eye for me programming side projects on my work laptop. Licensing aside, which is its own hot-topic.