It seems, that the creation of secondary explosions is not working as intended.
When the vehicle is destroyed, the script to start the secondaries is launched on every connected client. ([[_v,_int],"BIS_fnc_effectKilledSecondaries"] call bis_fnc_mp;)
That script will then in turn keep creating "SmallSecondary" vehicles, that are all global. (_b="SmallSecondary" createvehicle (_v modelToWorld _effect2pos);)