Просьба вникнуть в код и найти потенциальные ошибки в каждом случае

3.5

    private void Collect(IService sr, ObjectCategories protection)
    {
            sr.WorkingSegments.Cast<ServiceSegment>()
            .Concat(sr.ProtectionSegments.Cast<ServiceSegment>())
            .SelectMany(s => s.SegmentParcels.Cast<SegmentParcel>())
            .Select(p => p.NetworkConnection)
            .Where(nc => (nc != null))
            .Execute(nc => Collect(nc, protection));
     }

2.0

    private void Collect(IService sr, ObjectCategories protection)
    {
      List<ServiceSegment> segments = new List<ServiceSegment>();

      foreach (ServiceSegment item in sr.WorkingSegments)
        segments.Add(item);
      foreach (ServiceSegment item in sr.ProtectionSegments)
        segments.Add(item);

      foreach (ServiceSegment segment in segments)
      {
        foreach (SegmentParcel parcel in segment.SegmentParcels)
        {
          if (parcel.NetworkConnection == null)
            continue;

          Collect(parcel.NetworkConnection, protection);
        }
      }
    }