usually using Trade instead of Barter.
I can say with reasonable confidence that barter is safe, it never happened to me, that's how I exclusively trade and I did it a lot, like visiting every merchant before recruiting, leveling up or resting.
I also asked in order to reproduce and document it correctly, if it can help...
Shovel still won't talk to me. I am sad, I enjoyed our little 'conversations'...
just out of curiosity, where do you summon it ?