HSA's are tax free...it is taken out of your pay before you are taxed. You can't say that about your bank stash. But then again whenever the gov is. Involved it's always a f-up somehow.
In your case the money going into an HSA would be done by you, taxed at the time it came out of your paycheck but then written off when you do you taxes by adjusting your income. Another thing to possibly check with an accountant on.