Program: 158291
Project: 158291
Buggy source:
@Override public boolean apply(Game game,Ability source){
  Permanent permanent=game.getPermanent(source.getSourceId());
  if (permanent != null) {
    if (objectReference == null || !objectReference.refersTo(permanent,game)) {
      abilitiesToAdd=new HashSet<>();
      this.objectReference=new MageObjectReference(permanent,game);
      String keyString=CardUtil.getCardZoneString("String_Node_Str",source.getSourceId(),game,true);
      List<Card> delvedCards=(List<Card>)game.getState().getValue(keyString);
      if (delvedCards != null) {
        for (        Card card : delvedCards) {
          if (!card.getCardType().contains(CardType.CREATURE)) {
            continue;
          }
          for (          Ability cardAbility : card.getAbilities()) {
            if (cardAbility instanceof FlyingAbility) {
              abilitiesToAdd.add(FlyingAbility.getInstance());
            }
            if (cardAbility instanceof FirstStrikeAbility) {
              abilitiesToAdd.add(FirstStrikeAbility.getInstance());
            }
            if (cardAbility instanceof DoubleStrikeAbility) {
              abilitiesToAdd.add(DoubleStrikeAbility.getInstance());
            }
            if (cardAbility instanceof DeathtouchAbility) {
              abilitiesToAdd.add(DeathtouchAbility.getInstance());
            }
            if (cardAbility instanceof HasteAbility) {
              abilitiesToAdd.add(HasteAbility.getInstance());
            }
            if (cardAbility instanceof HexproofAbility) {
              abilitiesToAdd.add(HexproofAbility.getInstance());
            }
            if (cardAbility instanceof IndestructibleAbility) {
              abilitiesToAdd.add(IndestructibleAbility.getInstance());
            }
            if (cardAbility instanceof LifelinkAbility) {
              abilitiesToAdd.add(LifelinkAbility.getInstance());
            }
            if (cardAbility instanceof ReachAbility) {
              abilitiesToAdd.add(ReachAbility.getInstance());
            }
            if (cardAbility instanceof TrampleAbility) {
              abilitiesToAdd.add(TrampleAbility.getInstance());
            }
            if (cardAbility instanceof VigilanceAbility) {
              abilitiesToAdd.add(VigilanceAbility.getInstance());
            }
          }
        }
      }
    }
    for (    Ability ability : abilitiesToAdd) {
      permanent.addAbility(ability,source.getSourceId(),game);
    }
    return true;
  }
 else {
    if (abilitiesToAdd != null) {
      abilitiesToAdd=null;
    }
  }
  return false;
}

Fixed version (ground truth):
@Override public boolean apply(Game game,Ability source){
  Permanent permanent=game.getPermanent(source.getSourceId());
  if (permanent != null) {
    if (objectReference == null || !objectReference.refersTo(permanent,game)) {
      abilitiesToAdd=new HashSet<>();
      this.objectReference=new MageObjectReference(permanent,game);
      String keyString=CardUtil.getCardZoneString("String_Node_Str",source.getSourceId(),game,true);
      Cards delvedCards=(Cards)game.getState().getValue(keyString);
      if (delvedCards != null) {
        for (        Card card : delvedCards.getCards(game)) {
          if (!card.getCardType().contains(CardType.CREATURE)) {
            continue;
          }
          for (          Ability cardAbility : card.getAbilities()) {
            if (cardAbility instanceof FlyingAbility) {
              abilitiesToAdd.add(FlyingAbility.getInstance());
            }
            if (cardAbility instanceof FirstStrikeAbility) {
              abilitiesToAdd.add(FirstStrikeAbility.getInstance());
            }
            if (cardAbility instanceof DoubleStrikeAbility) {
              abilitiesToAdd.add(DoubleStrikeAbility.getInstance());
            }
            if (cardAbility instanceof DeathtouchAbility) {
              abilitiesToAdd.add(DeathtouchAbility.getInstance());
            }
            if (cardAbility instanceof HasteAbility) {
              abilitiesToAdd.add(HasteAbility.getInstance());
            }
            if (cardAbility instanceof HexproofAbility) {
              abilitiesToAdd.add(HexproofAbility.getInstance());
            }
            if (cardAbility instanceof IndestructibleAbility) {
              abilitiesToAdd.add(IndestructibleAbility.getInstance());
            }
            if (cardAbility instanceof LifelinkAbility) {
              abilitiesToAdd.add(LifelinkAbility.getInstance());
            }
            if (cardAbility instanceof ReachAbility) {
              abilitiesToAdd.add(ReachAbility.getInstance());
            }
            if (cardAbility instanceof TrampleAbility) {
              abilitiesToAdd.add(TrampleAbility.getInstance());
            }
            if (cardAbility instanceof VigilanceAbility) {
              abilitiesToAdd.add(VigilanceAbility.getInstance());
            }
          }
        }
      }
    }
    for (    Ability ability : abilitiesToAdd) {
      permanent.addAbility(ability,source.getSourceId(),game);
    }
    return true;
  }
 else   if (abilitiesToAdd != null) {
    abilitiesToAdd=null;
  }
  return false;
}