Let me ask you about an edge case: someone carries out an arson attack against a clinic providing abortion services and inadvertently leaks clues to their identity when gloating about it on social media, which information finds its way into the hands of law enforcement.
(to downvoters, that's something that happens and I have a specific and recent case in mind)
I think the downvotes are because your description doesn't make any sense. Can you rephrase the scenario to better describe what you mean?
Are you saying "Someone carries out an arson attack, they (the attacker) leaks clues to their (the attacker's) identity when gloating about it on social media, and those gloat-posts find their way to law enforcement?"
How does that scenario relate to Google data retention? Google data retention has nothing to do with Twitter policies.
It relates to Google data retention because law enforcement's next move might be to ask Google for geofenced location data from the 72 hours preceding the attack in hopes of confirming the arsonist's identity.
(to downvoters, that's something that happens and I have a specific and recent case in mind)