  A M-class behind-the-limb solar flare on 1 May 2013 (SOL2013-05-01T02:32),
accompanied by a ($\sim$ 400 km/s) CME was observed by several space-based
observatories with different viewing angles. We investigated the
RHESSI-observed occulted hard X-ray emissions that originated at least 0.1
\solrad{} above the flare site. Emissions below $\sim$10 keV revealed a hot,
extended (11 MK, >60 arcsec) thermal source from the escaping CME core, with
densities around $10^{9}$ cm$^{-3}$. In such a tenuous hot plasma, ionization
times scales are several minutes, consistent with the non-detection of the hot
CME core in SDO/AIA's 131 \AA{} filter. The non-thermal RHESSI source
originated from an even larger area ($\sim$100 arcsec) at lower densities
($10^{8}$ cm$^{-3}$) located above the hot core, but still behind the CME
front. This indicates that the observed part of the non-thermal electrons are
not responsible for heating the CME core. Possibly the hot core was heated by
non-thermal electrons before it became visible from Earth, meaning that the
un-occulted part of the non-thermal emission likely originates from a more
tenuous part of the CME core, where non-thermal electrons survive long enough
to became visible from Earth. Simultaneous hard X-ray spectra from the Mars
Odyssey mission, which viewed the flare on disk, indicated that the number of
non-thermal electrons $>$20 keV within the high coronal source is $\sim$0.1 -
0.5\% compared to the number within the chromospheric flare ribbons. The
detection of high coronal hard X-ray sources in this moderate size event
suggests that such sources are likely a common feature within solar eruptive
events.
