For MD 600 Driver:
No, you are not an employer - you are a kindly person who allows others to share your good fortune by getting some otherwise-unavailable stick time. You don't appear to be an AOC holder doing commercial work, and the low-timer (is he endorsed on type?) is not actually tasked to perform a job, just enjoy the ride.
The "employers" I was referring to are the mustering types who expect a queue of low-timers to be willing to be hangar slaves. There is one chopper, and only one pilot gets to fly it. He is not paid, and he is expected to sign up for the dole in the nearest town to get enough money to live. When this pilot gets some time up or is sufficiently disgruntled with the situation, he moves on and the next slave moves into his still-warm seat.