On 14 September 2001, under stongly northward IMF conditions Cluster registered several fast magnetic field polarity changes which are usually attributed to thin (near-equatorial) current sheet crossings. However, the IMF was northward for the previous 24 hours, the plasma sheet was expanded vertically, filled with cold, dense plasmas with high local vertical magnetic component Bz, and the formation of a such cross-tail thin current sheet was very unlikely. The analysis of multipoint measurements revealed that the detected sheets were almost vertically oriented, had strong shear and vanishing normal magnetic components, and therefore could be interpreted as boundaries between independent magnetic field domains (flux tubes) vertically indented relative to their neighbors, rather than crossings of the main cross-tail current sheet. Such field reversals would be then observed by a spacecraft owing to horizontal flapping motion. Similar events were detected under analogous conditions by a pair of Geotail and Interball spacecraft, providing important evidence of significant spatial extent of areas with indented magnetic flux tubes along the tail. In conclusion we suggest how such anomalous structured magnetotail configuration might emerge in the course of high-latitude reconnection of geomagnetic lobe and northward IMF.