I use the push/pull method and I have had one issue. I was stringing a Martin Savannah, and the string slipped out of the groove after I thought it had locked in. That particular bow has shallow grooves, and when it slipped out the bow jumped up with powerfull force, and hit me wright in the corner of my eye, between my eye and nose.
I instantly hit the ground thinking my eye had been knocked out, but once I regained my composure I realized I was alright. It just glanced off my eye and most of the impact was on my nose. I still had light flashes from my eye for about 6 month.
About a year later I was at Bob Wesley's house taking lessons, and I told him about the inccident. He advised me to never look at the bow when stringing it using the push/pull method, always look away.
That was a little over 5 years ago and til this day I still follow his advice to the letter.