The relevant result from relativity is that you cannot rely on synchronized clocks to construct an unambiguous ordering of events. Latency by itself is not sufficient to cause this, as the system could still wait until the message has been fully distributed, then use the timestamps to reconstruct the timeline.
However, CS does have to deal with this issue for the simple reason that we are already unable to synchronized our clocks to the extent necessary to avoid it (or, at least, it is not worth the engineering effort to do so).