Maybe I am missing something in this logic, but yet it is just an opinion, and no proof:
In this “naive” scenario, middleman Bob still has to trust Alice and Carol. Bob has to trust Carol to really give him the value after he sent her a bitcoin, and Bob has to trust Alice to really give him a bitcoin once he presents her the value.
The bitcoin-for-value trades must therefore be absolutely guaranteed along the network. More specifically: if Bob gives a bitcoin to Carol, he must be guaranteed to get a bitcoin back from Alice.
That's where Hash Time-Locked Contracts (HTLCs) come in.
For sure, when it is money, we trust a lot, in Bitcoin world we trust the mathematical rules, not a person. Not sure what the author means by "Bob has to trust Carol". The author should explain, what happens, when Carol plays wrong, and what are the lightning protections to prevent this. IMHO, this has nothing to do with HTLCs. If Bob feels that Carol is not playing honestly, he can close the channel immedeatly... before the HTLC time locks in. Also the author doesn't explain, why multisig addresses are "funky". The multisig addresses can be seen as simple checks, where two or more people must sign, to validate it - what is funky about this?
Can't make up my mind yet, having difficulties to follow the logic in this article.
I hope some more enlighted people will explain