If David had fired a blank from a Makarov pistol in contact with his temple, two discrepancies with this episode would have occurred. First, the shot would have killed him because the pressure would have pierced and then filled his skull; this is exactly how actor Jon-Erik Hexum killed himself. Second, no brass fragments would have separated from the case. This never happens because a blank cartridge case is crimped at the mouth to form a bullet-like profile, and all it does is open slightly upon firing.
It is a surprise that the author did not know that if a suitcase exploded, the legs of the carrier would be blown off, and the suitcase in pieces. If it were outside, then the suitcase dented and the blast marks coming out of the floor.