Program: 10519
Project: 10519
Buggy source:
@Override public boolean execute(ScriptEntry theCommand) throws CommandException {
  Integer duration=null;
  Direction direction=null;
  Location theLocation=null;
  LivingEntity theEntity=null;
  DenizenNPC theDenizen=theCommand.getDenizen();
  if (theCommand.arguments() != null) {
    for (    String thisArgument : theCommand.arguments()) {
      if (plugin.debugMode)       plugin.getLogger().log(Level.INFO,"String_Node_Str" + theCommand.getCommand() + "String_Node_Str"+ thisArgument);
      if (thisArgument.matches("String_Node_Str")) {
        if (plugin.debugMode)         plugin.getLogger().log(Level.INFO,"String_Node_Str");
        try {
          if (CitizensAPI.getNPCRegistry().getById(Integer.valueOf(thisArgument.split("String_Node_Str")[1])) != null) {
            theDenizen=plugin.getDenizenNPCRegistry().getDenizen(CitizensAPI.getNPCRegistry().getById(Integer.valueOf(thisArgument.split("String_Node_Str")[1])));
            if (plugin.debugMode)             plugin.getLogger().log(Level.INFO,"String_Node_Str");
          }
        }
 catch (        Throwable e) {
          throw new CommandException("String_Node_Str");
        }
      }
 else       if (thisArgument.matches("String_Node_Str")) {
        if (plugin.debugMode)         plugin.getLogger().log(Level.INFO,"String_Node_Str");
        duration=Integer.valueOf(thisArgument.split("String_Node_Str")[1]);
      }
 else       if (thisArgument.matches("String_Node_Str") && plugin.bookmarks.exists(thisArgument.split("String_Node_Str")[1],thisArgument.split("String_Node_Str")[2])) {
        theLocation=plugin.bookmarks.get(thisArgument.split("String_Node_Str")[1],thisArgument.split("String_Node_Str")[2],BookmarkType.LOCATION);
        if (plugin.debugMode)         plugin.getLogger().log(Level.INFO,"String_Node_Str");
      }
 else       if (thisArgument.matches("String_Node_Str") && plugin.bookmarks.exists(theCommand.getDenizen(),thisArgument.split("String_Node_Str")[1])) {
        theLocation=plugin.bookmarks.get(theCommand.getDenizen(),thisArgument.split("String_Node_Str")[1],BookmarkType.LOCATION);
        if (plugin.debugMode)         plugin.getLogger().log(Level.INFO,"String_Node_Str");
      }
 else {
        for (        Direction thisDirection : Direction.values()) {
          if (thisArgument.toUpperCase().equals(thisDirection.name())) {
            direction=Direction.valueOf(thisArgument);
            if (plugin.debugMode)             plugin.getLogger().log(Level.INFO,"String_Node_Str");
          }
        }
      }
    }
  }
  if (theLocation != null)   look(theEntity,theDenizen,direction,duration,theLocation);
  if (theEntity == null && direction.equals(Direction.AT))   theEntity=(LivingEntity)theCommand.getPlayer();
  if (direction != null)   look(theEntity,theDenizen,direction,duration,theLocation);
  return true;
}

Fixed version (ground truth):
@Override public boolean execute(ScriptEntry theCommand) throws CommandException {
  Integer duration=null;
  Direction direction=null;
  Location theLocation=null;
  LivingEntity theEntity=null;
  DenizenNPC theDenizen=theCommand.getDenizen();
  if (theCommand.arguments() != null) {
    for (    String thisArgument : theCommand.arguments()) {
      if (plugin.debugMode)       plugin.getLogger().log(Level.INFO,"String_Node_Str" + theCommand.getCommand() + "String_Node_Str"+ thisArgument);
      if (thisArgument.matches("String_Node_Str")) {
        if (plugin.debugMode)         plugin.getLogger().log(Level.INFO,"String_Node_Str");
        try {
          if (CitizensAPI.getNPCRegistry().getById(Integer.valueOf(thisArgument.split("String_Node_Str")[1])) != null) {
            theDenizen=plugin.getDenizenNPCRegistry().getDenizen(CitizensAPI.getNPCRegistry().getById(Integer.valueOf(thisArgument.split("String_Node_Str")[1])));
            if (plugin.debugMode)             plugin.getLogger().log(Level.INFO,"String_Node_Str");
          }
        }
 catch (        Throwable e) {
          throw new CommandException("String_Node_Str");
        }
      }
 else       if (thisArgument.matches("String_Node_Str")) {
        if (plugin.debugMode)         plugin.getLogger().log(Level.INFO,"String_Node_Str");
        duration=Integer.valueOf(thisArgument.split("String_Node_Str")[1]);
      }
 else       if (thisArgument.matches("String_Node_Str") && plugin.bookmarks.exists(thisArgument.split("String_Node_Str")[1],thisArgument.split("String_Node_Str")[2])) {
        theLocation=plugin.bookmarks.get(thisArgument.split("String_Node_Str")[1],thisArgument.split("String_Node_Str")[2],BookmarkType.LOCATION);
        if (plugin.debugMode)         plugin.getLogger().log(Level.INFO,"String_Node_Str");
      }
 else       if (thisArgument.matches("String_Node_Str") && plugin.bookmarks.exists(theCommand.getDenizen(),thisArgument.split("String_Node_Str")[1])) {
        theLocation=plugin.bookmarks.get(theCommand.getDenizen(),thisArgument.split("String_Node_Str")[1],BookmarkType.LOCATION);
        if (plugin.debugMode)         plugin.getLogger().log(Level.INFO,"String_Node_Str");
      }
 else {
        for (        Direction thisDirection : Direction.values()) {
          if (thisArgument.toUpperCase().equals(thisDirection.name())) {
            direction=Direction.valueOf(thisArgument);
            if (plugin.debugMode)             plugin.getLogger().log(Level.INFO,"String_Node_Str");
          }
        }
      }
    }
  }
  if (theLocation != null)   look(theEntity,theDenizen,direction,duration,theLocation);
 else   if (theEntity == null && direction.equals(Direction.AT))   theEntity=(LivingEntity)theCommand.getPlayer();
 else   if (direction != null)   look(theEntity,theDenizen,direction,duration,theLocation);
  return true;
}