WADS56, GOOD JOB. You may have prevented a much more serious accident that could have occurred from this truck driver's stupidness. Out of all the drivers on the road, truck drivers are some of the best, but there are of course a few that are just idiots (esp if he was really only 1-1.5 car lengths behind you). I'm sure he was pissed, but I'm also sure he had second thoughts later about riding on people's butts in blizzard conditions.
I say good job b/c while something worse
could've happened, it
didn't and a warning, that could save lives in the future, was given to the retard truck driver .
On your part however, a friendly tap of the brakes (just so he would see your brake lights for a second or 2), just so he could know that you wished him to BACK OFF, would've probably gotten it through his head. If not, a slightly more aggressive tap of the brakes might have. I would not advise the same type of behavior on your part in the future b/c the accident you may be trying to avoid may be 10x worse b/c of your slightly over-reaction (if that's a word). It was "blizzard conditions" so perhaps
slamming on brakes going from 35 mph to 3mph with an 18-wheeler behind you at about 1-1.5 car lengths wasn't the wisest thing to do--- ya think?
Your girl was angry at you b/c you endangered her (and other people on the road) life. What if the driver was looking to the side or something or for some reason wasn't able to stop in time? What if he plowed into the back of you? Even at 35mph? remember, you were going 3 and that was a semi..... Your day would've been screwed in the LEAST.
Your idea was good, but taken just a little to an extreme. Really think b4 you decide to do something like that in the future. Think about the possible consequences of those actions and how you could maybe refine your actions to avoid something worse then you might expect. I'm pretty sure you didn't count on the whole truck sliding to the side and almost wrecking. You were probably scared as crap as it was happening and was like "oh crap this guy is gonna wreck and turn over and it's gonna be my fault", but it didn't happen so you felt you did the right thing. Well, sorta. Just try not to be so extreme next time.
All in all, I would advise against you slamming on brakes to get people off your tail. Try a different/safer approach.