It also helps that the power level is low, so not much current is being switched. The primary side basically doesn't care about stray inductance (the switching impedance is close to the transmission line impedance for traces of that construction), and the secondary side may well benefit from the extra inductance (since, as you can see, diode recovery is slowed down, intentionally, using ferrite beads). If nothing else, the transformer dominates in LL and Cp.
Tim