How the heck did you twist that?
The papal Church does not say that "ek tou Patros kai tou Uiou ekporeuomenon" is heretical.
You are contradicting yourself. 
That is why the Orthodox Orient has always refused the formula to ek tou Patros kai tou Uiou ekporeuomenon and the Catholic Church has refused the addition kai tou Uiou to the formula ek to Patros ekporeumenon in the Greek text of the Nicene-Constantinopolitan Symbol, even in its liturgical use by Latins.
The formula above cannot be used WITH the addition of "from the Son" because it then DOES make the double procession a causal and originating one.
You see there are two ways of conveying procession in Greek...NEITHER one does what the Latin does which is to have the capacity to express BOTH the originating procession and the sourcing non-originating procession both in the same word.
You cannot do in Greek what you can do in Latin...no matter how hard you try.
I was not contradicting myself. It is NO-GO in both Greek examples.
PS Michal: Please pardon. We both got tangled for different reasons so now I see what you were saying to me about my Church saying that you cannot add
from the Son to the phrase above...You simply cannot add it to either one:
One makes it a double causal procession and the other leaves out the causal procession altogether...while the Latin form includes both types of procession and it does so by including Filioque to give context for the second type of procession.