I just noticed you're Canadian. You may have been in 4LO.
HA HA HA!! I'm glad no one's at the office yet to notice me randomly laughing at my computer!!
I still maintain, no way in 4 Low. Maybe the DIAL was in 4 Low and you never switched out of drive to actually let it change?
No, tow mode doesn't disengage 4 Low. Once you are IN 4 Low, the only thing that disengages it is the dial, and only when you are in neutral (or is it park? I forget, but it tells you on screen). It would be very bad for it to actually try to switch out of 4 Low while in motion.