It wasn't that Mr Weasley wouldn't get enough time to examine his sons for injuries. Nearly all of them had shown up to take part in the battle, with the exception of Charlie still abroad somewhere to tend to his dragons. And though they had all survived, some would have permanent injuries for the rest of their lives. Bill obviously had his scars and could add more after the battle. Percy and Fred had been caught in a mixture of spells and hexes blowing up between them and no one had been able to find the rest of Fred's left arm or Percy's right arm. Fred was already starting to make jokes about joining himself to Percy's hip to form a complete man. Percy was obviously already very annoyed. George seemed to be the only one with only a few knicks and bruises.