Small Weapons Teams and Moral Checks

Are small weapon teams also forced to take a moral test, if they loose 50% of their unit?

For example: Panzerschreck team weapon surived the shooting of a tank with one of two Guys alive. Does the suriver have to do a test?

We had this situation last game and both players thoughts was that this makes small weapon teams very vulnerable, but we coulnd't find anything in the rules against that moral check.

May you can point me to that, if there is a rule about it.