a bot-program?

[Fighter]

I don't know is it an in-game bug or a person was using a bot-program, but on the 14th of September I was mining together with a person ([Removed by moderator]) who !! in stealth !! was moving faster than me and every time it seemed as she was falling from somewhere above. When I wrote to her asking how it can be, i got no reply. It looked like she disappered at one place and in a few seconds appeared at another falling from the rock She was a miner of 14 level.
I hope somebody knows what it was and what to do with it.