It wasn't an "attack", the chain had a mechanism to mine it and that mechanism was utilized. It's, literally, that simple. Calling it an "attack" is, as I pointed out earlier, the same as saying that a miner with 40 1080TIs is "attacking" the network because you only have an RX 480. 

OK, let's pretend I'm not as knowledgeable as I actually am for a second:
Explain, exactly, how creating valid blocks, which are recognized by consensus, can "do harm to Safecoin" (especially since it's "Secured by Bitcoin")....

The equivalent hashpower of over 128,000 1080 ti's (700 Sol/s each) were pointed at the SafeCoin network during the attack. The overall network speed was driven from 300 KSol/s to 90 MSol/s. 1 MSol alone would have been enough for a 51% attack and capture a majority of the blocks. A bug was exploited by jl777B that him to generate blocks instantly. This stuck the chain, though we eventually mined through it before doing a rollback and fork. Before the problem was resolved he joined the discord to boast about what he had accomplished and attempted to provide a solution. The fixes he recommended were a load of bull. He invited others to FUD. Regardless of what you may think, jl777B orchestrated the attack. He mentioned that the exploit used led to the largest explosion in difficulty for KMD. It's not something you can claim to forget. Thousands of blocks were mined within this period. There was a community vote for a rollback when the fork was applied that fixed this problem.

jl777B has a history of malicious practice
http://blog.bluemeanie.net/2014/10/nxtautodac-jl777-stolen-nxt.html