That seems to be some sort of presentation bug. If you go check out the game now, and play around with the realtime=????? in the URL, you'll see it actually played out correctly.
The substitutions may be a different matter. It's possible that your starters were really tired from the first 4 quarters (they did play a lot of minutes), but we'll look into this for you.
So, sorry, no replay :-) But if you're starting to lose in the last Q and overtime, and want your starters to play more, you might try training stamina for a couple weeks.