[phunkyfish]

No, unfortunately not. Have seen various discrepancies. 
First noticed the issue in December.

 I would definitely raise this as a github issue. If it changes over time my guess is it will be tricky to find the cause but no one might be aware of it. You will need a debug log and screenshots (which you have). Just be clear about the fact it's your own skin and that as it's not displayed in the default skin because that field is not used.

Before you raise the issue can you check the duration of the programme before and after the one with the error. It's possible it's picking up the wrong EPG entry and using that instead which could mean it's a bug in the addon and not Kodi proper.