<p>The mechanisms of void-mediated dynamic ductile failure are discussed in the context of a recently proposed indicator of void coalescence. The indicator is developed based on unit cell calculations within the confines of a continuum description and inertial effects. Here, it is shown that this indicator may inevitably be satisfied in a loading program as a mere consequence of pressure-sensitive plastic flow. Furthermore, insofar as an indicator is not just meant to interpret unit cell results, but rather be used in structural simulations of dynamic failure, the proposed indicator cannot be used as basis to develop a void coalescence criterion. When interpreted in light of recent advances in micromechanical modeling of void growth and coalescence, the reported on unit cell calculations are found to confirm the conclusions of prior work in the literature, the most important of which being that dynamic loading may frustrate internal necking as a potent mode of void coalescence such that the latter would rather occur by mere impingement. A basic formulation of concurrent failure criteria (internal necking versus impingement) under dynamic loading conditions is presented with open questions highlighted for future research.</p>