  Recent data of the HADES Collaboration in Au+Au central collisions at
$\sqrt{s_{\rm NN}}=2.4$ GeV indicate large proton number fluctuations inside
one unit of rapidity around midrapidity. This can be a signature of critical
phenomena due to the strong attractive interactions between baryons. We study
an alternative hypothesis that these large fluctuations are caused by the
event-by-event fluctuations of the number of bare protons, and no interactions
between these protons are assumed. The proton number fluctuations in five
symmetric rapidity intervals $\Delta y$ inside the region $\Delta Y=1$ are
calculated using the binomial acceptance procedure. This procedure assumes the
independent (uncorrelated) emission of protons, and it appears to be in
agreement with the HADES data. To check this simple picture we suggest to
calculate the correlation between proton multiplicities in non-overlapping
rapidity intervals $\Delta y_1$ and $\Delta y_2$ placed inside $\Delta Y=1$.
