Ann: Investor Webinar Presentation, page-31

I wondered the same thing.
Then again, stating the causes of delays requires identifying the contractor who messed up (even if they aren't named). Maybe with skilled workers so hard to come by, companies are not willing to name and shame for fears of further delays? Or maybe it's just considered bad form?
Interesting question though, as to why not just come out and state the causes of the problems as it clearly irritates many shareholders and undermines trust.