This misunderstanding isn't on me. It's not on others to understand what you mean regardless of what you say, it is on you to speak precisely. If you're going to use "lol" in extremely insensitive contexts like this, you can expect people to be unhappy with you. For 35+ years now "lol" has been shorthand for laughing at something because you think it is funny. You're never going to write "lol" in such a way that anyone will interpret it as some sort of nuanced "this is laughable" statement, especially when you write it it all caps imply that you are having a hard laugh.
With that said, nothing about this is funny, and no use of "lol" here is appropriate as it sounds celebratory at worst and dismissive at best.