NO NO NO NO!!! the switch is not an approved ground source by the NEC AT ALL WHAT SO EVER!!!
Not a single one of the switches that E or D use are approved for being used as a ground source by the NEC, if this guy is grounding your system to the switch then he is an idiot, grounding of the coax and system is to be done between the dish and the switch to provide the switch and receivers with the best possible protection from static and lightning dish charge.