Full quote: "The irony is that, as near as I can tell, they cratered their balance sheet because they were heavily into long maturity bonds (i.e. super conservative)."
What exactly makes you think that the "(i.e. super conservative)" remark is not about "long maturity bonds" - which is the think that he just referenced?
He didn't mention Treasuries at all. I find quite difficult to interpret the "super conservative" as being about some kind of long-maturity bonds relative to another kind of long-maturity bonds.
Within the set of long-maturity bonds, Treasuries are conservative. That doesn’t make them conservative per se.