This is a known issue. Just last week, I replaced my radiator out of preventative maintenance. The transmission cooler/engine coolant line corrodes due to dissimilar metals, and the steel washer forcibly pulls the fitting out of the threads, causing this failure.
Whether or not your transmission has been damaged, it really depends on how much coolant is inside of the transmission. Ethylene glycol found in engine coolant creates a hydrophobic barrier around the bearings in the transmission which effectively prevents the bearings from being properly lubricated. Your best bet is a transmission rebuild, or better yet, complete replacement.
You'll find plenty of other posts regarding this exact issue on these forums. Just do a quick search.
Have your radiator replaced with a Koyo radiator, or at least something not the same as OEM. As far as I know, Honda hasn't modified the design of the fitting since 2006. Something with brass fittings would be ideal. Also, please file a complaint with the NHTSA, stating your current mileage and be sure to note how this could be a potential safety issue.
When you have some down time, I strongly advise writing Honda (good old snail mail) a letter that includes documentation of your failure, total repair cost, and photos. Best case scenario, Honda reimburses you the cost of repair. Send three letters to the addresses below (originally posted by csimo).
Honda Automobile Customer Service
1919 Torrance Boulevard
Mail Stop: 500 - 2N - 7A
Torrance, CA 90501-2746
Honda North America, Inc.
ATTN: Tetsuo Iwamura
700 Van Ness Av.
Torrance, CA 90501
Honda R&D Americas, Inc.
21001 State Route 739
Raymond, OH 43067-9705
All that being said, you should really pursue your warranty. This is NOT going to be a cheap fix (sorry). Even once your radiator has been replaced and transmission flushed, there is a good chance your transmission will eventually fail due to the reasons I discussed above. Pursue transmission replacement or have it rebuilt.
Make sure you find all available service records including oil changes and routine maintenance. Most extended warranty companies will ask you to produce proof that you have not neglected your vehicle.