No Foul.
I do have a question for more experienced umpires. I had a similar block in a game this season - both OGs fired out onto NG and the C appeared to be trying to pull. IYO, is this correct execution or is somebody blocking the wrong guy?
In the situation I had, the C was actually tripped by his LG and wound up crashing down on the NG as well - helmet to knee. I never saw the scheme again in that game or any other. I felt it had to be a mistake which resulted in a rather ugly collision.