Scanning my records of Rockies Comeback Wins/Blown Lead Losses after 7th Inning, last night vs. Padres was indeed the worst ever in team history (giving up a 7-run lead after 7th) . The closest I could find was a game at Pittsburgh in August 2003 when the Rockies gave up 6 runs in the bottom of the 9th to lose 12-11...
(L) 8-01-03 VS. PIT (ROAD): AHEAD 11-6, GAVE UP 6 RUNS BOT 9TH TO LOSE 12-11.
Fans may remember a similarly frustrating loss at home vs. Milwaukee in May of last year...
(L) 5-11-18 VS. MIL (HOME): AHEAD 9-3 AFTER 4TH; 10-8 AFTER 8TH; GAVE UP 2 RUNS TOP 9TH (2-OUT, 2-RUN HR), 1 RUN TOP 10TH AND LOST 11-10.
Point is, it's one stinging bad loss and happens in baseball. The May 11 debacle last year also happened to be on a Friday night at Coors Field. The following game on Saturday, Kyle Freeland (at least the 2018 version) pitched a superb game for a 4-0 Rockies shutout win.