Carve gone wrong

Hello, I have yet to start reading about what caused my issue. I decided to ask first to perhaps find the answer easier. So today, after soldering my aviation plugs and setting up my controller box, I ran my first test carve. I chose a simple carve of 7 letters on MDF. Using the dewalt 611 and some 1/8 carbide double flute end mills it breezed through 6 letters, then with the jinx of my wife, it went haywires confusing the initial coordinate of the last letter twice. The first misplacement caused it to run into the 6th letter and since I used .15 tabs it was pushed out and saved somehow (Test anyway…). The second misplacement went wild approxiamately +6 -2 of the last letter initial misplaced starting point.
I chalked it up to my test laptop acting up because when I recarved the last letter 6 inches away it was fine. Is there any reason to assume the laptop wasnt the issue and it needs some tuning, if you know or this is the world of DIY CNC please inform.
Thank You,
“A fellow Carver”

I don’t have my carver up and running yet, but you might want to try providing the file you used to make the carve and the software used to send the gcode.