I'm not entirely sure if this is a bug or intended, but Withers just kinda' lets you pick pocket him. I Spent 5000 gold assuming it would just vanish, but when I saw "pick pocket" naturally, being the goblin that I am I had to try, and there it was my 5000 gold. Now taking that much all at once is impossible without a nat 20, but now I was curious, so I tried it, failed, and ran away expecting to be chased like any other NPC.
Nope
So I went huh- and kept trying over and over and over until I got a nat 20, stood up, walked in front of him, talked to him, and he did his normal dialog like I didn't just shove both fists in his robe for the last 10 minutes. And this continued, I could pick-pocket him whenever I wanted without any repercussions at all. Also this wasn't one save file, I finished my first playthrough and made a new character, went over him to change Shadowheart to a better cleric, and boop, stole my money back after 3 failed rolls with 0 issue
Something tells me this isn't exactly intentional