I don’t think the projector is heavy enough to tear itself open just by gravity.
The battery is right underneath the deformed bottom panel (see Teardown by Paul Bruss - Technical Topics - Philips Projection). If a high capacity battery overheats, it can expand which would cause the deformation of the housing.
A swollen battery is at high risk of being punctured and causing a violent fire (youtube has many videos of failing/punctured phone batteries; the battery in the PPM has a LOT more energy stored in it). I would keep that projector turned off and away from anything you value (ie: preferably in a watertight container outside your house), until you hear from Philips Projection.