To start with, your measurement to your bottom limb should never be more than the top limb. It should be even, or maybe slightly more on the top limb. So the tech was right to set the tiller to zero for you. However...

If the tech simply adjusted the tiller to even, then it's likely the nockset moved downward in relation to your rest. You'll need to adjust your nockset and peep sight. Be sure to measure the distance between your nock and peep before moving either one. It'll make resetting the peep a little easier when you know the distance it needs to be from the nock.

Setting your tiller to zero might have even screwed up the timing on your rest, so be sure and check that.

IMO, these are things the tech should have checked and gone over with you before sending you out the door.