From what I can find on the timeline:
4:20 AM -
A flash flood warning is issued for the Hunt area. This does not include Kerrville. I can't find the NWS text but I've found multiple timestamps referring to it being called at 4:20 am.
From an Austin Met - "4:20 AM - RARE FLASH FLOOD EMERGENCY ISSUED for western Kerr and Bandera counties until 7 AM!
Life-threatening situation unfolding due to 10" of rain in just the last few hours. The heaviest rain is now moving out of this area, but the damage is done.
Fast-rising waters on creeks, streams, and rivers here. Please avoid driving if at all possible!"
Edit: Found the NWS alert. Something to note is that all images I can find only box off Western Kerr county. It doesn't extend down the Guadalupe River until 5:34 AM.
BREAKING NEWS ALERT - LIVES AT RISK!! - KERR COUNTY TEXAS - THIS IS NOT A DRILL.
IF YOU ARE NEAR THE SOUTHFORK OF THE GUADALUPE RIVER OR IN A FLOOD PLAIN NEAR THE GUADALUPE RIVER GET! OUT! NOW!
From NWS: Much of Highways 27 and 39 will flood as the disastrous flood wave moves downstream over the next several hours. Motorists should avoid any travel in the flood plain. Low residences above Center Point to below Comfort will flood. Many homes and businesses in Kerrville will flood.
The National Weather Service has declared a FLASH FLOOD EMERGENCY!!!
Guadalupe River at Hunt affecting Kerr County.
* WHAT...Major flooding is occurring and major flooding is forecast.
* WHERE...Guadalupe River at Hunt.
* WHEN...Until just after midnight tonight. (July 5)
* IMPACTS...At 32.0 feet, Disastrous life threatening flooding puts
water over the roads of lowest camps and resorts from the
headwaters of the North and South Forks to below Comfort. Much of
Highways 27 and 39 will flood as the disastrous flood wave moves
downstream over the next several hours. Motorists should avoid any
travel in the flood plain. Low residences above Center Point to
below Comfort will flood. Many homes and businesses in Kerrville
will flood.
Kerr County has experienced several devastating floods throughout its history. The worst recorded flood on the Guadalupe River at Kerrville occurred on July 2, 1932, reaching a staggering 39.00 feet.
Another significant and tragic flood was on July 17, 1987, when the river crested at 37.72 feet. This flood is unfortunately remembered for the loss of 10 lives, all teenagers on a church bus swept away by the raging waters near Comfort.
While many floods have impacted Kerr County, these two stand out for their extreme river stages and the tragic casualties associated with the 1987 event.
This is not a drill. Alert anyone you know in the affected areas NOW!
5:34 AM -
...FLASH FLOOD EMERGENCY FOR THE GUADALUPE RIVER FROM HUNT THROUGH KERRVILE AND CENTER POINT...
The National Weather Service in Austin/San Antonio has issued a
* Flash Flood Warning for... East Central Kerr County in south central Texas...
* Until noon CDT Friday.
* At 534 AM CDT, Automated rain gauges indicate a large and deadly flood wave is moving down the Guadalupe River. Flash flooding is already occurring.
This is a FLASH FLOOD EMERGENCY for the Guadalupe River from Hunt through Kerrvile and Center Point. This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER GROUND NOW!
HAZARD...Life threatening flash flooding. Thunderstorms producing flash flooding.
SOURCE...Radar and automated gauges.
IMPACT...This is a PARTICULARLY DANGEROUS SITUATION. Residents and campers should SEEK HIGHER GROUND NOW! Life threatening flash flooding along the river is expected.
* Some locations that will experience flash flooding include... The Guadalupe River at Hunt, Kerrville, and Center Point.
***
This says to me that people around Hunt would have gotten a phone alert at 4:20am and the people around Kerrville would not have gotten an alert until 5:34am. How many people could have made it to higher ground in an hour and 10 minutes? Camp Mystic probably had no chance, but heads in Kerrville should roll.
