This surprised me as even the Americans are starting to cool on the war and can't ignore reality for ever, when it's clear the Ukrainian offensive has not produced the required results, which means support for the war will wane among politicians in the United States.
Anyway, the journalist didn't ask for a source for the statement that the Ukrainians had broken through the first Russian line.
I was, a tad sceptical. It turns out the only sourde is the Kiev Post, a newspaper interviewing the Ukrainian Defence Minister, who didn't actully say they broken through the real first line of Russian defences, but only that they'd crossed a Russian line of defence. No on else, no independent source, has supported the Ukrainian version.