I agree - and in fact this probably covers the OP’s scenario - there are laws against just taking someone else’s shrubbery, but they are less likely to be enforced at the very small end of the scale.
Yeah, and I concede that in the age of social media, it is possible for a sort of flash mob type situation to be triggered, causing a genuine ‘everybody-trying-to-do-it’ situation.
Although that also happens when Jamie Oliver makes an interesting recipe - everyone rushes out and clears the shelves of the star ingredient.
Let’s recall the OP was not talking about taking a cutting. He needed the whole plant: roots, soil, and all.
And it’s obviously too late, and may have been a long shot even if it weren’t, but often landscapers do leave some sort of calling card in their landscaping. They’d be the best to contact. They may even be happy to see you take away a plant that otherwise they would need to dig up themselves.
Outlaws don’t care about your stinking laws.
True. I still think the right answer is to be inspired by the example and work patiently to reproduce it. If you really love bonsai, as opposed to just liking tiny trees.