There has been a lot of confusion over these flags. An article by Mark H. Dunkelman, an expert on the 154th NY, appears in The Gettysburg Magazine issue no. 29 (published by Morningside). Dunkelman devotes over five pages to the topic of the fate of the colors of the 154th and 134th at Gettysburg, sorting through all the varied and sometimes conflicting accounts. Summarizing, the 134th got both their colors back. However, it appears the 154th rescued their state colors but lost their national colors, even though one reference does indicate a member of the 134th rescued the 154th's national colors. It's true the latter flag's capture is not recorded in the Confederate official reports, but another source states unidentified Confederate veterans returned the flag after the war, so it is possible that a Confederate soldier kept the flag in his personal possession at the time of the battle. So now you get a sense of the confusion. This may be a mystery that will never be fully resolved to everyone's satisfaction.