negative latencies?

[nestmp () mntk org]

Hi - while scanning a fast network (95+% hosts repond <3ms),
using -T5, I see many reports like (tech detail at bottom):

Nmap scan report for W.X.Y.Z
Host is up (-0.90s latency).
PORT     STATE    SERVICE      VERSION
22/tcp   filtered ssh
23/tcp   filtered telnet
[...]

or

Nmap scan report for A.B.C.D
Host is up (-2.0s latency).
Skipping host 171.64.214.144 due to host timeout
Nmap scan report for I.J.K.L
Host is up (-2.0s latency).
PORT     STATE    SERVICE      VERSION
22/tcp   filtered ssh
23/tcp   filtered telnet


Note the negative latencies.  Our network isn't that fast!

Searching for 'negative latency' (and similar) brings up no hits I can
find.  Apologies if a duplicate/not a bug.

Thanks,
- m

[tech details]

nmap 6.4

/usr/local/bin/nmap -n --randomize-hosts -PE -PS22,23,80,433 -sS -p
22,23,80,137,443,445,8000,8008,8080 -sV --version-all -O --osscan-guess
-T5 --max-rtt-timeout 100ms --initial-rtt-timeout 4ms --min-parallelism
8 --min-hostgroup 1024 --stats-every 600s -sC -oA 'nmap_%D_%T'
INSERT_CLASS_B_HERE

# uname -a
Linux scanner 3.2.0-54-generic-pae #82-Ubuntu SMP Tue Sep 10 20:29:22
UTC 2013 i686 i686 i386 GNU/Linux

# cat /etc/issue
Ubuntu 12.04.3 LTS \n \l
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