I.G.
Nope, I would not have given it second thoughts. I absolutely hate all the germ paranoia out there. It is actually quite difficult to acquire HIV, unless you have unprotected sex or are injected with infected blood. Even touching infected blood carries relatively low risk of transmission.
Your husband is right, as he is getting older he will be exposed to other's blood, saliva and god knows what... so relax and keep on teaching him good hygiene (hand washing).
Good luck!