ipmi_lan_poll_recv assumes that the two "Send Message" responses will be consecutive. If this is not the case, the second response will be dropped. This was observed when a MicroTCA Shelf Manager sent a "Set Event Receiver" to ipmitool, assuming that it was a Carrier Manager. The "Set Event Receiver" would often appear between the "Send Message" ack and the bridged command response.
I have looked at the code, but I don't see an easy way to fix this.