I always consider myself lucky when I get cut, they could always be worse. I've been so luck a few times when the machete could have done serious damage. You guys are exactly correct about using technique, not power, and staying focused.
I've had machetes bounce off my leg, looked down to see no cut on my pants, boy that was close! One time I swung my Swamp Rat Waki with too much power and my arm swung around so far that I felt it nick my achilles tendon. That was just a very small scratch, but just imagine how bad that could have been.
Thursday night I was cleaning a Case canoe, both blades open, Q-tip was too thick, pulled too hard, and bam! I cut the meat of my thumb just above the knuckle, it's a 1.24" long gash, bled like crazy. It was "distracted" according to the ER doc, meaning it was flailed open, looked like your shin in the pics. I knew it needed stiches, 4 to be exact. I worked in the culinary industry for 12 years, I've seen lots of cuts, and this one was not going back together, it was too deep.
Heal well and stay focused!