I have huge sympathy for Robert Kubica but I cannot understand why a serious F1 team would risk hiring him.
I can't work out if they were on like for like tyres but he was a smidge under 2 seconds a lap slower than the already not very impressive Stroll during today's test. There are young drivers in the lower ranks that could probably beat that without any health and mobility concerns and I would expect / hope that DiResta's experience would have resulted in much better times. Robert has already had an insurance pay-out because his career had been terminated due to the accident - I applaud him for wanting to get back into F1 but I think there is too much risk.
Yeah, he's been given his chance, and if he's not up to it, it wouldn't be fair to him, his team or the driver he would be displacing.
I'm disappointed he isn't ready to return to F1.
However, only Williams (and probably Pirelli) know what conditions he ran with.
(Maybe it was a negotiating ploy. 'Robert, you were slow at the test, but maybe we'll sign you on for a low offer...')