Macroscopic dynamics of the hydrodynamic (Lamb) impulse JV induced by the chaotic vortex filaments in the counterflowing superfluid turbulent HeII is studied. Both the Lamb impulse and its dynamics are considered on the basis of the Gaussian model of chaotic vortex tangle elaborated earlier by one of the authors (S.N.). The rate of change of the quantity JV is shown to be equal to the force Fsn exerted by the normal component on the vortex tangle. That contradicts the obvious fact that in steady case the quantity JV should have a constant value. Resolving that apparent paradox we draw some conclusions concerning the stochastic dynamics of the quantized vortex lines.