Hello Thea,
It is because in Implementation Class CL_BT116S_S_ADVANCEDSP_IMPL, there is a GET_V_SALES_ORG method which is actually coming from CL_BTSRV_ADVS_CNTRL.
This leads to the call of CL_THTMLB_F4HELP=>GET_HELP_VALUES when you click on the F4 help icon. Please try to redefine this method GET_V_SALES_ORG in CL_BT116S_S_ADVANCEDSP_IMPL.
Best Regards, Corrine