Temperature, crush, water volume and PH could all affect the gravity. With the unusual crush method, the changes in water volume and temperature, they could all affect the PH (notwithstanding the original water chemistry).
So look for consistency - meaning brew the same recipe a few times using the same methods to identify areas that need to be tweaked and refined. Focus on one aspect at a time to tweak.
First, have the LHBS double crush your grains for you so that you get fairly consistent crush going forward. Later you can ask him to adjust the crush or mill your own as desired.
Secondly, don't sweat that temperature. As already posted, you were probably in a good temperature to begin with that you could have just left it be and had good results. You have more flexibility in mash temperature than you realize. Single step mash (as in BIAB) uses a compromise temperature to blend the temperature ranges of the two desired reactions. Anything in the low 150s will generally result in a decent beer. So for now get close and focus in holding it there.
Thirdly, (at some point in time, but sooner is better) get a water report (most municipalities will provide them online) and a reliable PH testing kit/device for home brewing. The grains should naturally take the PH down to a good range (5.4 - 5.6 give or take depending on a few things) but this may not be the case for particularly hard or soft water. There is some good information on water chemistry here and some easy calculators to help if your mash PH is off. You really need only know 5 numbers, Calcium, Magnesium, Chloride, Sulfate and Alkalinity. FWIW, I've been brewing fairly decent beer but not consistently. I though my PH strips were no good - kept reading 5.0. Finally took a look at the published water chemistry and whaddayaknow. My Calcium, Magnesium and Sulfate were all below John Palmer's recommended ranges - which accounted for lower mash efficiency (via low PH) and the unbalanced flavors. My water is great from drinking, longevity of my plumbing and sparkling clean glassware, but it needs a little help for brewing. Either do this starting on your next brew, or wait until you have some more brews under your belt and still are not hitting your numbers.
Since we are chasing gravity in home brew. Know your water volumes, especially your evaporation rates. I use a measuring stick and an excel spreadsheet so I can quickly take a volume reading at different times (initial, after adding the grains, pre-boil, post boil and cooled). If you over shoot with too much water, you can continue the boil to get to your desired volume.
And, I always keep light DME on hand. If I miss my gravity by more than couple of points, I can use a calculator in my software (many have this ) and quickly boil up and add some DME to bump up the final numbers which makes me happier.