Unless they have direct evidence of someone else magically doing it without any of them noticing (like if they all went up to go to the restroom with their drinks on the table, at the same time, and a bystander did it, which police would never do in the first place..), this was the quickest 'investigation' on planet earth. And no explanation for the magical bleach appearance.
The only explanation I could imagine, is that they tested the rest of the shake in the machine, and all of it was tainted with bleach. That still doesn't mean someone didn't pour it in there to target the officers, at least it doesn't in my mind, but it makes for a more plausible excuse that they weren't singled out.
Unless they have direct evidence of someone else magically doing it without any of them noticing (like if they all went up to go to the restroom with their drinks on the table, at the same time, and a bystander did it, which police would never do in the first place..), this was the quickest 'investigation' on planet earth. And no explanation for the magical bleach appearance.
The only explanation I could imagine, is that they tested the rest of the shake in the machine, and all of it was tainted with bleach. That still doesn't mean someone didn't pour it in there to target the officers, at least it doesn't in my mind, but it makes for a more plausible excuse that they weren't singled out.