Hey, part of the reasons for this jam is to help each other find bugs and glitches. I'm glad I can help.
I was just editing my post to mention that I haven't tried starting a new game after a loss on today's patch. I had started playing last night, and just left the game up so I could come back to it today. I did refresh the page to try again (I was playing on the web), but I only did one run.
I'm not sure what was causing the screen filling laser. The first time it happened was right as I was using Therapeutic Grapple, but I had just used Snipers Legacy as well. I don't think I used Snipers Legacy the second time it happened, though I used the ability so many times I can't be 100% sure one way or another. Given how often I used Snipers Legacy, it didn't even occur to me that it might have been the cause of the screen filling laser.
One of the kids just let me know that they got the screen filling laser as well. They had used Snipers Legacy and had missed. I know I missed with it the first time it happened, so it does seem like a good place to start looking.