Query on the HREF Overflow database (April datadump):
SELECT COUNT(*) as num, ToQuestionId, ToSite
FROM Links WHERE ToSite = FromSite
GROUP BY ToQuestionId, ToSite ORDER BY num DESC LIMIT 1
Result:
282|1732348|so
(number of SO-internal outbound links from that question: 3).
JavaScript command on that question pagequestion page:
>>> $(".linked").find("a").length
300
So: I guess no (or possibly 300).