As GT suggests, there may have been a problem at the maltings although it's unlikely, they have been doing it for years and supply commercial brewers and the type of brewer to use this malt is less likely to tollerate any hazes as the beers are less likely to be filtered. I believe some of the multi nationals aren't worried whether they get a haze as it'll be filtered out, it's cost and yield that are important to them.
The only thing I can think of is might a condition like cask fretts where a small amount of o2 is introduced at racking and along with a small amount of remaining available sugars it can kick a mini fermentation but the yeast aren't able to complete their cycle and sit their stubbornly and don't move. To avoid this it's important to rack at an SG and not a specific time frameand to pitch the correct amount of yeast, this recipe would have required a 2.5L starter.
If this is the case then time is the only cure, especially now it is bottled, it is unlikely though that the haze has anything to do with the malt assuming it was genuine MO suppplied.