You're way off in how the figures are made.
The DRF speed rating and variant have nothing at all to do with it. They are just put in the form for 80-year-old people who used them as a rule of thumb growing up. They give speed handicapping a horrible name.
As far as Fifth of April's last race ... the winner ran 6 furlongs in 1:12 4/5ths.
Earlier in the card, a $5,000 N3L claiming race went six furlongs in 1:11 flat and later on in the card a different $5,000 N3L claiming race went six furlongs in 1:11 and change.
Regarding the horse who went 1:11 flat ... he came back and finished 7th in a 10K claimer race at Hawthorne ... these are his PP's...
A speed figure can be "wrong" for a few different reasons ... sometimes the race isn't timed correctly or the final time gets typo'd.
Sometimes the track changes speeds because of track maintenance or weather ... stuff like that.
However, the speed rating/variant has nothing at all to do with the Beyer figure and it is without question the most worthless piece of information you will find in the past performances.