Unless he was spraying a low dose natural product like neem or euc oil etc he'll be cutting time of his calendar.
I bet it was an insecticide.
You know, inside our house I use a fly swat rather than spray, and I'm a 99.9% striker. You get the odd fly come in, why spray that crap everywhere ... SWAT the buggers and that's it, more satisfying too!
Just clean the blood and guts up with a tissue and chuck him in the bin.
