Re: mold in grass
You can plant sod or in just about any weather/temperature, but it is critical that it is handled properly during that time.
If you are in 115* weather, then your ground should have been completely prepped and fully saturated with moisture, that is to say, the ground should have been just shy of mud, dry and firm enough to walk on, before the sod arrived. The sod should have been freshly cut from the producers farm and laid as quickly as possible. The longer it sits on a pallet, the more stunted and prone to death it will be.
I've never been a big seed person, it takes a whole lot more attention and trouble than sod. Sod is instant green, and as long as you prepped correctly, got fresh sod, and keep it wet, it's going to stay green. The yard is useable almost instantaneously, as opposed to seed that can take months to fill in to the point of being tolerant of even mild traffic.
On your question of mold, if your sod did mold, it was likely moldy when you laid it, due to being rolled and day old. If this was the case, then the sod was too old to be used anyway.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!