I think this happens with all macros, but since I do not have access to any macros that perform a function similar to "print," I can only say, for sure, that it happens with print:
>>> print "omfg" if 6666 < 0
omfg
>>>print "lawl" if 1d > 321d2h1m84s
lawl
>>>
Both statements are obviously false.
#should just print okay once:
print "okay"
print "okay" if 100 < 0
print "okay" unless 10 > 9
print "holey", "moley" unless 10 > 9
#this works (although booi has no debug option)
debug "debug1" if 100 < 0
debug "debug1", "debug2" if 100 < 0
#this works too:
#print "hit ctrl-C to stop" while true