Crazy lag

My schwarz-bier  brew day went well.  My only issue was a poor lauder.  This was caused by some channeling down the side of my MLT.  I have switched my MLT return hose to a longer length and will make sure a keep a few inches of water above the grain bed.  I still hit the mid 80’s so I only missed my OG by a few points.  I cooled the wort to 75° and transferred to two carboys.  They were placed in my fermentation chamber and cooled to 45° overnight.  I aerated the wort with pure oxygen then pitched half the starter into each.  Here is where things get interesting, or not interesting depending on how you look at it.  Nothing happened.  There is normally more lag time with a lager but this was crazy.  Five days in and still nothing.  I shook up the carboys over the next few days and started to get solid fermentation activity after a week.  I did pitch a good amount of yeast, around 1.7M cells / mL / °P with a two step starter (1.5L & 4L).  A few days ago I checked by gravity and had hit 1.014 so the temperature has been increased slowly to 62° for a diacetyl rest and to finish fermentation.  The sample tasted good with little noticeable diacetyl.   I think what occurred was the starter was cooled down too low while the wort was cooled from 75 to 45°.  It was in the same fermentation chamber as the wort.  I do not think it froze but cooled enough for the yeast to go dormant and the initial pitch at 45° was not enough to wake them up.  Once the fermentation started it took off very quickly and was vigorous enough to need a blow off tube.  It should be ready to start lagering in a few days.