On slide 196, the probability of being homozygote given \(F\) is given as \(P_{AA}=Fp_A+(1-F)p_A^2\). Thus, an inbred individual with inbreeding coefficient \(F\) is \(Prob(AA|F)/Prob(AA|0)=F/p_A+(1-F)\) more likely to be homozygote than a non inbred individual. Lets plot this:

ratio.hom<-function(p,f) f/p+(1-f)
p<-seq(0.001,0.1,0.001)
plot(p,ratio.hom(p,f=0.125),type="l",log="x",ylab="Ratio Homozygosity",lwd=2)
abline(h=1,col="red")

Imagine we are looking at a rare recessive disease. An inbred individual, when the allele frequency is low, is many times more likely to be affected than a non inbred individual.