In all honesty, it's karlovic's fault. If he withdrew around the same time nadal and monfils, I think haas would've made the trip to London.
Edit: was haas even on the alternate list?
I dont think it is Karlos fault. He seems like fair guy, he knew he cant play if he limped on crutches few days ago. But problem is : there are lot of "Support team " in every country delegation : coaches, doctors, national Olympic Committe officials. More athletes from certain country means more support team from same country. If Karlo withdrew too early, before accreditation, one member of support team has to leave also.
We have same problem in Estonia. If an athlete qualifies to Olympics, they send him, injured or not, in form or not, because more athletes means more support team.And every sports official wants to be on Olympics, they dont want to go home because one athlete is injured and cannot compete ...