so far ive been ignoring anything i see such as cracked glass,scratches or fogged windows because where would it end .  i have just assumed the owner already knows about it.  but 2 houses have got me thinking recently . 
 no.1   has a huge picture window in the lounge and from the first i was there i see a 2 inch crack at the side about a third of the way up, probably hasnt been noticed by the owner . will it spread,it hasnt so far.... could i be blamed ?
 no.2 this house has big glass,everythings perfect and the owners picky and last time i went to clean i noticed what looks exactly like a fresh bullet hole high up on a bedroom window .nobody was home the day i cleaned 
  what do you do ?