In the paper, data from direct numerical simulation of an incompressible planar turbulent flow in a strained channel (Jeyapaul et al., 2015) are used to investigate relations between derivatives of the streamwise mean velocity in the wall-normal direction, turbulence production by the shear, the shape of probability density functions of velocity fluctuations in the streamwise and wall-normal directions, and balance errors in the DNS budgets of velocity moments up to the fourth order with the focus on the flow near-wall area. As time progresses, the flow undergoes deformation leading to its separation. A new criterion based on the streamwise mean velocity second derivative in the wall-normal direction is proposed to rigorously define the buffer zone boundaries. It is shown that the balance errors have the systematic contribution in this flow area. The errors are also the highest in comparison with the turbulence production in the buffer zone at any time. The most affected are odd- and even-order velocity moments with odd exponents of the velocity fluctuations. The systematic error in the data is suggested as a likely explanation of the deformed shape of the probability density function of the velocity fluctuation in the streamwise direction observed in the buffer zone at early times of this flow development. Unresolved reference data are of concern for modeling as they may mislead the modeling effort and the model quality assessment.