J.T.
I can't comment on the specific procedure but, in general, there is no absolute prohibition against turns below 400ft. Indeed, many terrain-critical departures are based on turns from the runway head or a waypoint prior to 400 ft ..
Perhaps you might be confusing this with the certification requirement that the OEI third segment minimum height is 400 ft above runway elevation ? .. regardless of whether there be a turn or not ...
John, I am not sure about PANS-OPS but in a country that uses U.S. TERPS, the minimum altitude for commencing a turn on any instrument departure is 400 feet, unless a higher altitude is specified. Or, in some case a fix/waypoint will be provided as the initial turn point, but it will be designed so no turn will be required below 400 feet.
OTOH, OEI procedures can, and often do, specify a turn below 400 feet. (Sometimes, well below 400 feet, but limited to a 15 degree bank angle.)