While that is true in general, it is not always the case if you read those articles i linked to earlier. Just simple LR can lead to AMPUTATIONS if you get unlucky on what grows there. It is RARE, but something you should consider.
There are also several species of corals that can "spit" water and have highly dangerous toxins. If it hits you in the eye, it can be very destructive. Again, your best defense is rubber or plastic gloves and KNOWING WHAT YOU HAVE in your tank.
If you are going to raise that highly poisonous stuff on purpose, get a pair of shop glasses. 9999/10000 times you wont need them, but when you do you will be glad you have them.
Most of the poisons and infections you can get from your SW tank are VERY poorly understood, and the time it takes to properly diagnose them can really let them mess you up.
An ounce of prevention is worth 200 lbs of liverock any day!
***Ridiculous story***
When i was just beginning to learn about setting up a FOWLR tank i ran across the wetwebmedia articles i linked to earlier in this post.
I went to my LFS and was talking to the rep that i liked there about those articles. He said to me "Well, when you think about it, the bacteria found in a SW tank are much more likely to thrive in your blood than the bacteria found in a FW tank as the chemistry is closer".
I thought about that a second and couldn't come up with a good counter-argument as blood IS quite salty.
He then looked into the saltwater reef aquarium we were standing in front of and must have spotted a problem. He moved a few rocks (some with corals attached) and brought his hands out. He dried them with paper towels and them proceeded to suck on a cut he had received.
He is still alive of course, but i have never thought of him as an expert in quite the same way