I may be misinterpreting the question, but I think that the question was more like this:
Employee, age 60, terminates from Company A, and begins working at Company B (unrelated to Company A). Rolls 401(k) money from Company A's plan to Company B's plan. Let us assume that the employee also contributes to the Company B plan.
Time passes, and the participant, still working for Company B, has attained age 70 1/2. Does the employee have to take a minimum distribution on the portion of the 401(k) balance derived from the Company A rollover, or is the fact that the employee is still working for Company B enough to push off having to start taking RMDs?
Would one get a different answer if the employee had not contributed to the Company B plan, so the entire balance in the Company B 401(k) plan is entirely attributable to the rollover from Company A?