Normally, when you design a targeted tax credit for businesses, the eligibility requirements tend to be backward looking. They say that if you paid so much in tax or your earnings were a certain amount the year before, then you're eligible for this, and then what you do next year you may get a tax credit for. The proposal here was designed a little strangely: that the eligibility criteria was forward looking, that your actions next year determine whether or not you're eligible for the credit. You can find yourself in a situation where you look to be paying too much in EI, thus making yourself ineligible for the credit. By either delaying hiring, reducing hours, or in extreme measures firing people, you can actually make yourself eligible for the credit.
It was just, in my view, a design error. Had the design been backward looking instead of forward looking, I think there may be some merit to the idea.