98 Honda Accord tire issues

ay so 2 months ago my car went into the
shop and i had 4 new tires put on and a
new alignment done. 2 Months later I'm
driving down the road and i start to hear a
knocking and suddenly my passenger tire
flys off and my car luckily ends up on the
side of the road. The mechanic states
because i have 3 lug nuts on it that's y that
happened and wont pay for the repairs
now. Am i crazy or are they wrong? I don't
know what to do i had 3 lug nuts on the
drivers side too and didn't have that
problem. Would it not be negligent for them
to let me drive it the first time? 2 months
ago?