This was my gig, and yes, the client was not happy with the volume of the DJ. He worked from a laptop/Serato/sampler setup, and the levels varied wildly not only from track to track but within each section as he mixed everything together. There was no choice but to run it relatively hot and squash it to keep it within reason so we didn't hear grief about the quieter sections as well.
Not to mention that fact that he had his own monitors run from his mixer, and the high end there was pegged negating half of what we tried to accomplish. Unfortunately, we were the ones that had to deal with the client, they were not willing to make any comment, or authorize us to, as the DJ was at one time a very big name.
The whole story may have been different if we had the 1500 expected and not the 90 that showed up.