Gumu is off the hook.
Check it out:

The zookeeper that was hospitalized last month due to a zebra bite was not following protocol in dealing with a particularly aggressive zebra, an investigation by the National Zoo determined.

On November 18, a zookeeper was taken to the hospital after being bitten several times by Gumu, one of the zoo’s male Grevy Zebras.

Grevy Zebras are considered to be dangerous animals, and zoo policy is to maintain a barrier between such animals and any staff. At the time, it was not clear why that proper protocol had been observed.