Recent optical studies in c-axis oriented superconducting MgB_2 films indicate that the electron-phonon coupling is weak [tu01]. We reinforce this conclusion by examining the raw reflectance data; its frequency dependence is incompatible with strong electron-phonon scattering. This is further strengthened by analysis of the real part of the conductivity, and by the temperature dependence of the effective Drude scattering rate. Using a realistic electron-phonon spectral shape [kong01], we find

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... tr≈ 0.15, in agreement with Tu et al. [tu01]. To the extent that λ_ tr≈λ, this disagrees sharply with model calculations [kong01,kortus01,an01], and is far too low to provide the means for T_c = 39 K. A simple model is constructed with coupling to a high frequency excitation, which is consistent with both the low frequency optical data and the high T_c.