Cause for concern ?

[caranjoy]

Coming back from a 2 week holiday was informed by the cat sitter ,who has known Max and lizzie since they were kittens and still are that Max after nearly a week and a half of her stay decided to urinate over her whilst she was sleeping . I am at my wits end as to why he should do this as we like to take the odd break, but do not want to leave them at a cattery ,or leave them alone with just the daily vists from neighbours to feed and clean etc
They are completely happy with cat sitter loving around her sleeping on her lap I am just concerned that this might become the norm if and when we go away