Работа с Array. Ошибка "Array index out of range"

private static ArrayList<AboutTeam> team = new ArrayList<AboutTeam>();
public static void addInfAboutMyTeam(IWorkItem workItem) throws TeamRepositoryException{
        int is = isInList(workItem);
        if (is < 0){
            team.add(new AboutTeam(getOwner(workItem)));
            is = isInList(workItem);
        }
        try{
            int duration = (int) (workItem.getDuration() > 0 ? workItem.getDuration()/3600000 : 8);
            if (workItem.getWorkItemType().equalsIgnoreCase("defect")) team.get(is).addDefect(duration, 
                    workItem.getSeverity().toString().substring(workItem.getSeverity().toString().length() - 2, workItem.getSeverity().toString().length())); 
            else team.get(is).addTask(duration);
        } catch (Exception e){
            System.out.println("is = " + is);
            System.out.println("team.size = " + team.size());
            System.out.println("Error : " + e.getMessage());
        }
        
    }
    
    public static int isInList(IWorkItem workItem) throws TeamRepositoryException{
        for (int i = 0; i < team.size(); i++){
            if (team.get(i).getOwner().equals(getOwner(workItem)))
                return i;
        }
        return -1;
    }