Am I being duped?

[FTD]

I paid someone to put new drop links on my car. I know what they are, where they are, and that it is simple to get to and do, but I thought what if I don't get the bolts tight enough or something like that. I am not a mechanic, just also not ignant and my Dad taught me a lot. But, I decided for the price, convenience, and confidence I would just let this shop do it. Kewl.

Well, I have discovered wheel vibration at 75+ mph. So I called the guy and said I want to bring the car by so he could check the installation. He said - "you need a balance".

OK - why didn't he say something about that initially? Like, once we put these new ones on you are probably going to need to get the wheels balanced. We can/can't do it or we can recommend a place or whatever. Who in the world picks up their car not wanting to be informed of outstanding work?

Secondly, I cannot logically understand how replacing drop links would disrupt balance. Two bolts attached to rigid parts - how did that alter my wheel balance?

Is this guy for real, or is he a fake and I need to go back and present a case to him?