Beam Angle vs Viewing Angle
Don't trust the summary specs given by the distributor. The real spec is what's in the original datasheet issued by the manufacturer. 

AFAICT, the datasheet gives only an "emission angle" spec, with a typical radiant intensity vs angle curve on page 6:



Even the "typical" values and curves in the datasheet are not hard promises. Only the minimum and maximum value specs are actual promises from the manufacturer about the device performance.