They are as pure as Przewalski's horses. Somewhere in the linage were a few wrong animals, but they are the best chance we have. The line from Rabat is highly inbred, but for that matter very pure. They look distinctly different to other lions.
So better save what we have and not let these fantastic creatures die out, just because one or two lions in the past were the wrong subspecies. If we did so, we might loose other animals too! (I am looking at you, Amurleopard!)
I have the information by the colleagues that work on the breeding program and were in place in Rabat to make tests etc.
And still: If you say the Barbary lion is gone, so are the Przewalski's horses then.
Yeah , I don't buy it at all, sorry for my frankness but I think there are far more worthy causes in conservation for actual extant species and populations that are far more deserving of all the funding that has been flushed down the toilet on "Barbary" lions over the years.