What’s the difference between Harvey Weinstein and the Pillsbury Doughboy? When the Doughboy offers you a roll, he doesn’t ask you to watch him take a shower first.
OUCH! Flash burn SUCKS! I've only had indirect burn from arc reflections off of stainless steel and that sucked. I can't imagine how bad direct, up close and personal burn was! Glad you're recovering well!
I agree with the opinions/diagnoses already stated. Overcrowded and possibly over-fertilized. Once a week is too much. The cumulative effect is burning the plants.