I only have the blog post to go by, and don't have first-hand information. It seems possible to me that a few packets could indeed be delayed by 90 seconds, perhaps stuck in a switch buffer somewhere, although this would be a small number of packets since those buffers are not very big.
However, yes, I was thinking about the network stack as a whole. Any kind of retries, e.g. TCP retransmission on timeout, effectively turns packet loss into packet delay (within certain bounds). Thus, even if you have a network interruption ("partition") and all packets are dropped, it could happen that after the interruption is fixed, a node receives packets that were sent before or during the interruption. For this reason, I find it helpful to think of it as delay, not just packet loss.
However, yes, I was thinking about the network stack as a whole. Any kind of retries, e.g. TCP retransmission on timeout, effectively turns packet loss into packet delay (within certain bounds). Thus, even if you have a network interruption ("partition") and all packets are dropped, it could happen that after the interruption is fixed, a node receives packets that were sent before or during the interruption. For this reason, I find it helpful to think of it as delay, not just packet loss.