That is once again rare nonsense. But somehow it is also indicative of the fact that you really can't be careful enough. Simply a shame and stressful.
The stress does not arise from the fact that mistakes happen, but from how they are dealt with. Often this begins with an accusatory tone that turns project partners into opponents - foolish if the project success is a common goal. Technical errors can be corrected much more easily than a destroyed level of communication. Substantially hard positions can be enforced far better and with fewer consequences on a good communication level than with loudness and lawyers. And also less stressful for all involved.
And anyone who believes that as a client they can
really watch out and control, overestimates themselves massively and will
always lose in an adversarial relationship with their service providers - maybe not legally or financially, but certainly mentally and qualitatively.