How can this happen?

https://uberchromegw.corp.google.com/i/chromeos/builders/ninja-release/builds/866
https://pantheon.corp.google.com/storage/browser/chromeos-autotest-results/101766331-chromeos-test/chromeos4-row3-rack9-host2/debug/

file autoserv.DEBUG:

02/17 06:23:52.879 DEBUG|          ssh_host:0284| Running (ssh) 'test ! -e /var/log/messages || cp -f /var/log/messages /var/tmp/messages.autotest_start'
02/17 06:23:52.951 INFO |      abstract_ssh:0809| Starting master ssh connection '/usr/bin/ssh -a -x   -N -o ControlMaster=yes -o ControlPath=/tmp/_autotmp_ajPK9Gssh-master/socket -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o BatchMode=yes -o ConnectTimeout=30 -o ServerAliveInterval=900 -o ServerAliveCountMax=3 -o ConnectionAttempts=4 -o Protocol=2 -l root -p 22 chromeos4-row3-rack9-host2'
02/17 06:23:52.951 DEBUG|        base_utils:0185| Running '/usr/bin/ssh -a -x   -N -o ControlMaster=yes -o ControlPath=/tmp/_autotmp_ajPK9Gssh-master/socket -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o BatchMode=yes -o ConnectTimeout=30 -o ServerAliveInterval=900 -o ServerAliveCountMax=3 -o ConnectionAttempts=4 -o Protocol=2 -l root -p 22 chromeos4-row3-rack9-host2'
02/17 06:23:58.014 INFO |      abstract_ssh:0824| Timed out waiting for master-ssh connection to be established.
02/17 06:25:01.341 ERROR|        base_utils:0280| [stderr] ssh: connect to host chromeos4-row3-rack9-host2 port 22: Connection timed out
02/17 06:25:01.343 INFO |            remote:0073| Failed to copy /var/log/messages at startup: ('ssh timed out', * Command: 
    /usr/bin/ssh -a -x    -o ControlPath=/tmp/_autotmp_ajPK9Gssh-
    master/socket -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null
    -o BatchMode=yes -o ConnectTimeout=30 -o ServerAliveInterval=900 -o
    ServerAliveCountMax=3 -o ConnectionAttempts=4 -o Protocol=2 -l root -p 22
    chromeos4-row3-rack9-host2 "export LIBC_FATAL_STDERR_=1; if type
    \"logger\" > /dev/null 2>&1; then logger -tag \"autotest\"
    \"server[stack::create_target_machine|create_host|job_start] ->
    ssh_run(test ! -e /var/log/messages || cp -f /var/log/messages
    /var/tmp/messages.autotest_start)\";fi; test ! -e /var/log/messages || cp
    -f /var/log/messages /var/tmp/messages.autotest_start"
Exit status: 255
Duration: 63.2917709351

There is a log entry at 06:23:51 about starting the master ssh connection, then about 6 seconds later at 06:23:58 another entry about the timeout.  That's too soon, we would expect the delay to be at least 30 seconds.  The next log line has a more reasonable time stamp.