While it's difficult to determine who is at fault in the Whaley-Epicor case, there are some possible explanations for what happened, according to experts.

ERP projects commonly have cost overruns, but the alleged quintupling of Whaley's implementation expenses "is above normal," said analyst Ray Wang, CEO of Constellation Research.

If Whaley's allegations are true, it's possible that the implementation team "didn't have a clear understanding of the capabilities of the software versus what was mapped out, and could not execute," Wang said.

At the same time, the workflows and process maps provided may not have been detailed enough for Epicor to produce an accurate estimate, he said.

Overall, the project's woes are familiar music to Michael Krigsman, CEO of Asuret, a consulting firm that helps companies with IT projects.