I think the question is how SPDY is any better than pipelining when encountering packet loss when both are built on TCP, and it is TCP that handles the re-transmits when packets are lost.
All I could find in the article is:
* SPDY sends ~40% fewer packets than HTTP, which means fewer packets affected by loss.
* SPDY uses fewer TCP connections, which means few changes to lose the SYN packet. In many TCP implementations, this delay is disproportionately expensive (up to 3 s).
* SPDY's more efficient use of TCP usually triggers TCP's fast retransmit instead of using retransmit timers.
But that is a comparison of plain (non-pipelined) HTTP to SPDY.