I assume this is just a variation of a standard glitch, but it was a first time it resulted in a triple play for me.
I was playing the CPU and it had bases loaded. The next batter took an 0-1 pitch and hit a lazy linedrive/pop up to my second baseman. As I was up 16-1 a the moment and was trying to prolong the game, I took a step back and shot-hopped it. The runners got confused and stayed frozen a few steps off each base. So I threw the ball home thinking that would get the other runners in motion, but it didn't so I just threw the ball around the horn for an easy glitch-assisted triple play.
Yeah, I've seen this runner frozen glitch, when they aren't sure if you are going to catch it and then they never run, sometimes I think they will go after the first force out.
EDIT:
Another baserunning glitch for the CPU is when they can't decide if they should tag up on a fly ball and just run back and forth stepping of 3rd base and then stepping right back on this usually stops when you finally throw the ball and they stay on 3rd, though occasionally they will decide to make a late break for home and get thrown out at the plate.