This is a really interesting play. From a strategy perspective the coach pulls this off with an 0-2 count and 2 outs. The thought being a hit at that point to score a run is unlikely. It makes gambling a strong option as the worst result is the hitter gets to lead off the next inning with a fresh start.
Some people think plays like this are bush league. I am not of that opinion. Runs are a sacred thing in baseball. Do what you can to get as many as you can.
Lastly, there is the rules aspect of it. The play by the offense is legal. Nothing in the rules about tripping during a steal attempt. Rule 7.08 (i) talks about running the bases in reverse making a “travesty” of the game (yup, that word is in the book). This rule was put in due to Herman Schaefer and his antics around the turn of the century. But this play is clearly not that.
The defensive side of this is more interesting. In the video, the defensive dugout is heard yelling something as the play begins. Most likely they are yelling “step off” or some variation. Why would they be yelling this?
Because the rules don’t allow a pitcher to make a fake to first base while on the rubber. If he would have lifted his front foot, he would have had to either throw to first, throw to home, or commit a balk. If he completed a turn, he could have faked toward second since a play was being made. But stepping back is the best option since once he steps back, he is treated like any other infielder.
On these double steals, the pitcher wants to be able to make a play on either runner if needed. Stepping off allows him to do this.
Balks are covered on pages 22 and 23 of RuleGraphics.