Guessing tho he may have ran them twice per week he didn’t do it properly. Frequency isn’t the key necessarily. Watering properly/adequately is the key. Since 1969 have been irrigating areas from lawn size to several hundred acres. Do it right or wasting your time, water, and $A neighbor across the street ran his sprinkler system at least twice a week all summer.
I didn't even activate mine at all.
Noticed yesterday, waiting for the clouds to do something, that his yard looks no better than mine. Patchy, lots of green, but brown spots dotted around.
I think it's just that time.