  Recently, an interesting dilogarithmic integral arising in quantum field
theory has been closed-form evaluated in terms of the Clausen function
$\text{Cl}_2(\theta)$ by Coffey [J. Math. Phys.} 49 (2008), 093508]. It
represents the volume of an ideal tetrahedron in hyperbolic space and is
involved in two intriguing equivalent conjectures of Borwein and Broadhurst. It
is shown here, by simple and direct arguments, that this integral can be
expressed by the triplet of the Clausen function values which are involved in
one of the two above-mentioned conjectures.
