We study the dependence of neutral current (NC) neutrino-induced $pi^0$/photon production ($ u_mu + A to u_mu +1pi^0 / gamma + X$) on the atomic number of the target nucleus, A, at 4-momentum transfers relevant to the MiniBooNE experiment: $Delta$ resonance mass region. Our conclusion is based on experimental data for photon-nucleus interactions from the A2 collaboration at the Mainz MAMI accelerator. We work in the approximation that decays of $Delta$ resonance unaffected by its production channel, via photon or Z boson. $1pi^0+X$ production scales as A$^{2/3}$, the surface area of the nucleus. Meanwhile the photons created in $Delta$ decays will leave the nucleus, and that cross section will be proportional to the atomic number of the nucleus. Thus the ratio of photon production to $pi^0$ production is proportional to A$^{1/3}$. For carbon $^{12}$C this factor is $approx$2.3. MiniBooNE normalises the rate of photon production to the measured $pi^0$ production rate. The reduced neutral pion production rate would yield at least twice as many photons as previously expected, thus significantly lowering the number of unexplained electron-like events.
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