Hope so for Dario. [ They checked him. The vet for your dogs? Not a Herp Vet ... ] Visual inspection done or what test done ?
Something did happen from the fall. [[ "didn't have big injuries " ]] ??? Blood… yes nothing visible wrong / nothing big to the eye. Shell strong yes , not broken yes but what’s going on internally ? Relative to Dario's size that's like you falling from 1500 feet !
Was any x rays taken and what kind ?
How good a doctor can read them matters too. A few offices the vet does all on his/her own no specialist in the office.
I know some still use a old film style x ray machine that does not show soft tissue well , this saves them money. Much better digital machines been around for some time and have a smaller footprint and offers much better / higher resolution than film x rays and cheaper for you. They show soft tissue very well. The fact spitting blood from the terminal velocity of the fall / 6 stories , to impact on plastic roof then from that to the first floor something very possible happened internally.
Is your vet a “herpetologist” / turtle specialist or dog and cat vet ?
Did a "radiology technician" take the x ray or the doctor ?
Did a radiologist “read" the x ray and make a diagnosis to the vet ?
Or did the vet do all ... ?
Lots of questions need answering still before the all clear .
In my career I found turtles yes are hardy but hide things well , another doctor ( Herp Vet that treats turtles) for diagnosis with a digital x ray needs to be seen , if "no" to any answers to above ...
Here's a link for Herp's :
http://www.anapsid.org/vets/