@douglashurdI had eStreamer Add-on v5.1.3 installed and believe the bytes-in/bytes-out and packets-in/packets-out are inverted.
raw event - SrcIP: [Internet-IP], DstIP: [Firewall-IP], InitiatorPackets: 1, ResponderPackets: 0, InitiatorBytes: 54, ResponderBytes: 0
parsed fields - src_ip = [Internet-IP], dest_ip = [Firewall-IP], packets_received = 0, bytes_out = 54,
raw event - src_ip= [Internet-IP], dest_ip= [Firewall-IP], src_pkts=1, dst_pkts=0, src_bytes=54, dest_bytes=0
parsed fields - src_ip = [Internet-IP], dest_ip = [Firewall-IP], packets_in=1 , packets_out=0, bytes_in=54, bytes_out=0
As you can see in the parsed events, that the syslog event indicates 54 bytes sent outbound, while the eStreamer logs indicates the bytes are inbound.
I believe the the raw logs in both cases indicate that the bytes were sent outbound, so I think the cisco:estreamer:data parser may be incorrect here.