Were you be able to get the same price with Google Flights?
Maybe if you are willing to share your date and route info, some FT members here can help.
Google flights and Matrix were providing essentially the same information. And that output was not bookable through AC.
Oddly enough I went to Expedia and found the flights that worked at the best price and my friends have now booked.
So the practical issue is resolved but I still wonder about the usefulness of either Flights or Matrix if the output is not bookable. I am still interested in FT's input on this as I thought that they were fairly reliable tools.