Mines

[Imp]

Not to mention you now have to clear them or risk setting off if you exit the hex.

[Kiwikkiwik]

So I rerun the tests with a bigger sample set, I dismounted 50 times into 50 hexes, each with 50 mines. Not a single explosion. If you walk into the same hexs from next hex then usually an explosion.
So I think it is safe to conclude that dismounting wether from a truck, glider or landing craft doesn't trigger mines.
Don't forget in a 3 minute turn you are not just jumping out, you will be spreading out as well.