row().node() doesn't take class names from cells

When I take the node of 15th row for example (oTable.row(15).node()) it gives me this output:

<tr> <td>13:00​</td>​ <td>22:55​</td> </tr>

But that row has class names in cells. If I find this row manually in table and right click/inspect element I see this:

<tr role="row" class="odd"> <td class="column-depTime">13:00</td> <td class="column-arrTime">22:55</td> </tr>

I noticed that some rows are copied with class names, some don't. Any ideas how to get class names? I tried with deferRender: false, but no luck.