That's fucking stupid. Florida has some weird law because they got rid of parole that states if you commit one of a listed offense in the statute, that you get a minimum sentence of 15 years. It's not something that needs to happen but apparently almost every attorney pushes for it which is a big reason Florida's prison population is retarded.
The biggest issue they had and the reason for the sentencing was because a 3 year old saw it. But during the testimony the witnesses who said they witnessed the child seeing it couldn't confirm that there was any penetration and they did not see any genitalia. The video doesn't show any penetration either. So basically their lives are ruined and they have to be considered sex offenders because of some dry humping.