DST is irrelevant for this discussion. On WIndows NT+, the system clock (as returned by libc ftime/windows GetSystemTime) is always in UTC (broken down to a Gregorian date). It is thus not affected by DST changes.

What does matter for this bug is administrator changes to the system time (like manual changes), and time adjustments due to NTP (although the Windows NTP implementation will perform a non-monototic change only during boot, AFAIK).