There is room directly beneath the bathroom. Something from this room was forced upwards, through the floor of the shower at an angle to smash the glass. Possible explanations include there was a boiler which exploded and some metal came up OR a bullet was fired upwards accidentally or something like this. The DI was then able to escape and repair the damage. The woman was another thief who happened to be have Phonophobia (fear of loud noises) and had a heart attack and died frm the boiler explosion and/or gun being fired. The DI then stole the ring and ran off (the visit to Cuba is optional).
Alternatively
For whatever reason, one pane of glass was shaped weirdly so that ,on a clear day at a certain date and time, the light from the bathroom window would hit the first glass wall, be refracted and bent through the shower to focus exactly on the second glass wall. The heat caused the second glass wall to smash allowing the DI to escape. However, when the glass exploded, the DI was injured at started bleeding. The woman was another thief who had hemophobia (fear of blood) and suffered heart attack at the sight of his injuries. The Di then took the ring and legged it.