Perhaps a madcap theory but nevertheless a possibility.
Parkgate Crescent lies directly under the 22 climbout from the City Airport and could have been subject to wake turbulence from the impressive display of the Airbus.
Hopefully here is a link to an article about wake turbulence illustrating the effects and dangers that can be caused.
http://www.nats-uk.ead-it.com/aip/cu...9_P_064_en.pdf
The article is quite long but the relevant parts appear to be
Para 1.3
Para 2.13 ( 1-4)
Para 3.1-3.5.1
Irrespective of the above the tiles or slates in question did not appear to be particularly sturdy looking.