Massive Parse Tree Failure in Logstash 5.0.0-alpha3

logstash-config-broken.conf - Starting Point

input {
  udp {
    host => "127.0.0.1"
    port => 9514
    type => "syslog"
  }
}
filter {
  # This grok FAILS with a PARSE ERROR
  grok {
    match => { "message" => "<%{NONNEGINT:syslog_pri}>%{SYSLOGBASE} %{GREEDYDATA:content}" }
    add_tag => "grok"
  }
  if "grok" in [tags] {
    syslog_pri {}
  }
  mutate {
    remove_field => [ "syslog_pri" ]
    remove_tag   => [ "grok" ]
  }
}
filter {
  if [content] {
   json {
      target => "[_data]"
      source => "content"
      add_tag => [ "data", "json" ]
   }
  }
}
filter {
  if [program] == "ossec" and [_data] {
    if [_data][component]  {
       grok {
         match => { "[_data][component]" => "\(%{IPORHOST:src}\) %{WORD}->%{GREEDYDATA:src_file}" }
         add_tag => [ "ossec_valid" ]
       }
    }
  }
}
filter {
    mutate {
        remove_field => [ "_json" ]
    }
}
output {
   stdout {
     codec => "rubydebug"
   }
}

logstash-doesnt-work-but-doesnt-fail.conf

input {
  udp {
    host => "127.0.0.1"
    port => 9514
    type => "syslog"
  }
}
filter {
  grok {
    match => { "message" => "<%{NONNEGINT:syslog_pri}>%{SYSLOGBASE} %{GREEDYDATA:content}" }
    add_tag => "grok"
  }
  if "grok" in [tags] {
    syslog_pri {}
  }
  mutate {
    remove_field => [ "syslog_pri" ]
    remove_tag   => [ "grok" ]
  }
}
filter {
  if [content] {
   json {
      target => "[_data]"
      source => "content"
      add_tag => [ "data", "json" ]
   }
  }
}
filter {
  if [program] == "ossec" and [_data] {
    if [_data][component]  {
      # ADDING this mutate causes the previous GROKPARSE error to go away, docs are parsed,
      #  BUT NOTHING happens to the message in this mutate, ie, the tag is not added, but the
      #  rest of the config works
       mutate {
           add_tag => [ "noop" ]
       }
       grok {
         match => { "[_data][component]" => "\(%{IPORHOST:src}\) %{WORD}->%{GREEDYDATA:src_file}" }
         add_tag => [ "ossec_valid" ]
       }
    }
  }
}
filter {
    mutate {
        remove_field => [ "_json" ]
    }
}
output {
   stdout {
     codec => "rubydebug"
   }
}

Possible Explanation: "Two filter operators become quantum entangled. Only one may run successfully, but both must be present for either to run successfully."