When I was renting, planes that were over 100 hours were flagged 'no dual'
in the rental signup sheets. (Usually for about a week, whenever they could
fit them into the maintenance schedule).. So I think your agrument is
valid. However, they may have an insurance related issue with renting
planes over the 100 hour inspection time.

--
Ben
C-172 - N13258 @ 87Y