We show that the hypothesis of regularity of the conditional distribution of
the empiric average of a finite sample of IID random variables, given all the
sample "fluctuations", which appeared in our earlier manuscript |1] in the
context of the eigenvalue concentration analysis for multi-particle random
operators, is satisfied for a class of probability distributions with
piecewise-constant or sufficiently smooth probability density. It extends the
well-known property of Gausssian IID samples