So sorry about your friend Tim...very sad! It's very rare in my neck of the woods to see a vehicle out on it only snow machines and 4 wheelers. What is scary here is the under ground hot springs that flow into most of our lakes. An area of a lake is open water and the other side of the lake would be frozen and a foot of ice. I know you have those in MT. being our geographic area with geysers and faults etc. and you are closer to Yellowstone than I am.
Bluegill tourney last week was scary for me..... though I was on 8" ice we had 40F day weather Fri-Sun..Sunday the ice was cracking all around me the whole time I was out! At one point I felt and heard a big rumble under my tush that scared me to the point of darting out of my chair and moving closer to the bank to fish. I fished alone most of the day.... boy I wished I could find a buddy that would go out all the time with me on ice. I have plenty of open water buddy's but they don't like the ice.
Again so sorry about your loss and the family. My prayers are with you.
Chin up and keep safe.
Smiles Always!
MA

DUCK TAPE USE #87: I found that duct tape works much better and quicker than spanking!