retirement from an employer versus controlled group

Suppose I have a one person defined benefit plan. The owner is in the 55-62 age zone. If he wanted to draw his pension but not terminate the plan could he stop working for company x and start working for a newly formed company y? Company y does not enter into any kind of joinder or participation agreement regarding the plan of company x. In other words, is retirement on a controlled group basis or can it be viewed purely from the standpoint of the plan sponsor. I realize  many of the rules we apply are on a controlled group basis but was wondering if this a valid scheme 

Severance of employment is on a controlled group basis.

Good Luck!