DrRacket doesn't currently know about the difference between those two
(it just evaluates the program and eval knows what it is doing, but
doesn't currently tell).
There is a related thing, tho: when debugging is turned off, if you
see a green bubble (it will have little spikeys on it), then clicking
run just starts from the compiled version that online check syntax
produced. That can speed things up a bit.
Robby