In the case you have above the installer wasn't reading his foam. They must be trained to do that as they spray. Temps and conditions are constantly changing thru out the day. Either he wasn't properly trained or if he was,he wasn't doing his job! This is a serious problem with people jumping in to the foam business. A lot of homeowners and builders are looking the best price and end up with someone who doesn't know what they are doing. Hope this info helps. Foam insulation is a great product. It just has to be done right by someone who knows what they are doing.
For example, a hybrid solution of spray foam and fiberglass batts or rolls combines the air-sealing and vapor-retarder benefits of foam with the economical thermal performance of fiberglass. Another option might be to install spray foam in places that are hard to reach or seal, such as rim joists, the attic floor, and eaves, and then install fiberglass batts and loose-fill in the in the open areas, greatly reducing any draftiness while helping the project budget. Incorporating spray foam into hybrid solutions enhances the building envelope and seals efficiently at a reasonable cost.
Sporadic cases of hypersensitivity pneumonitis (HP) have also been reported in workers exposed to isocyanates. The symptoms may seem like the flu, with fever, muscle aches, and headaches. Other symptoms may include a dry cough, chest tightness, and difficult breathing. Individuals with chronic HP often experience progressively more difficult breathing, fatigue, and weight loss. Individuals with acute HP typically develop symptoms 4–6 hours after exposure.