The target doesn't move, each employer contribution has its own vesting period which cannot exceed six years. In this case, the vesting period is two years, so any employer contributions within the last two years are subject to either partial or full forfeiture, depending on the terms of the plan.
Okay, then help me understand this. The guy has had a 401k plan there for 14 years. He should have been 100% vested at 6 years, so he's been 100% vested for 8 years. How is it the last two year's funds (his employment years 13 and 14) are not fully vested for him?