int motherId = mctrk[piplus[ipiplus].GetMcIdx()].GetMcMotherIdx();
if(motherId<0 || mctrk[motherId].PdgCode()==88888) {

theAnalysis->FillList(mctrk, "McTruth");
theAnalysis->FillList(piplus, "PionLoosePlus",pidalgos);
...
for (Int_t ipiplus=0;ipiplus<piplus.GetLength();++ipiplus){
  if (theAnalysis->McTruthMatch(piplus[ipiplus])){
    pidpiplus.Add(piplus[ipiplus]);
    RhoCandidate *mother = piplus[ipiplus]->TheMother();
    if(!mother || mother->PdgCode()==88888) {     <------------
    truepiplus.Add(piplus[ipiplus]);
  } else {
    falsepiplus.Add(piplus[ipiplus]);
    }
  }
}