Strangely enough somebody over on NowTV Twitter has reported the same exact issue (unless it was you).
Out of curiosity what playback device are you using ?
You may have to jump over to live chat to report this so they can investigate it further, where it sounds like a glitch or bug on their system or your account / playback device.
I just tried watching two episodes on Sky Crime boxsets and the live Sky Crime channel and i didn't get the on screen message about the Hayu Pass on my NowTV box.
You could try steps 1, 6 and 2 in this linked guide below but i doubt it will make any difference.
Otherwise you will have to report this to NowTV live chat.
To reach live chat open the link below and click on the small green arrow underneath How to Get in Touch to reveal the live chat button.
We're investigating this issue at the moment.
You should still be able to watch your chosen show by going to the Entertainment section and browsing the Sky Crime shows available On Demand.
If you have any questions or need any further help please let me know.