Relocated to California, need to return home. Help with verbiage of proration.

My husband and I relocated to California for his company. Due to family health issues, we need to head back home ASAP. Unfortunately there is no comparable position back home within the company. His contract states:
"These payments require a two (2) year employment commitment to [employer]. Should you leave the employ of the company within the first year of your start date, you will be required to pay the full grossed-up moving allowance. If you leave during the second year, you will be required to pay a pro-rated share of the moving allowance."

My question is, would the proration start after the completion of the first year of employment? (i.e. would the relo amount be split into 12 to determine amount owed) Or would they consider the amount to be half satisfied at the end of that first year? [i.e. split the relo into 24 equal payments, 12 of which are forgiven at the end of year one)

Also when it states the relocation amount, it is put as $XX,XXX NET. Then it is stated that he would be required to pay the full grossed up moving allowance. There was a SIZABLE difference between the net and gross. What dollar amount would they be going off of, since we only received the net amount.