  The kinematic reconstruction of neutral current high Q^2 events at HERA is
discussed in detail using as an example the recently published events of the H1
and ZEUS collaborations at Q^2 > 15000 GeV^2 and M > 180 GeV, which are more
numerous than expected from Standard Model predictions. Taking into account the
complete information of these events, the mass reconstruction is improved and
the difference between the average mass of the samples of the two experiments
is reduced from 26+/-10 GeV to 17+/-7 GeV, but remains different enough to
render unlikely an interpretation of the excess observed by the two
collaborations as originating from the decay of a single narrow resonance.
