https://github.com/bitcoin/bitcoin/blob/9ad6f14175c19b5d47267c3dd5840c14bad43c83/src/validation.cpp#L3711

If i'm following right the flow of the code, when we hit this lane `pindex` should be always equal to nullptr thus this check may be omitted
return ::ChainstateActive().InvalidateBlock(state, chainparams, pindex);
}
void CChainState::ResetBlockFailureFlags(CBlockIndex *pindex) {