And lots of people (me) are inclined to want to help and we answer questions without thinking we're under suspicion. It may not be wise, but it's not stupid. It's human nature to want to help with any information.
If you're innocent, why would clamming up and calling for lawyer be the first thing you should do? This is not a rhetorical question. Will a lawyer tell us? Would a lawyer ever tell someone who's innocent to cooperate with police and tell them everything they know without a lawyer being present?
I will never, ever understand innocent people doing that. Lying to police is never smart as he knows now, but not talking and asking for a lawyer indicates guilt more than lying, in my opinion. Who knows, maybe he slipped a bill out of the stack and was trying to hide that by lying?
I'm pretty sure police are used to people lying to them. It's not unusual, and it's a huge waste of time and resources, but it's not always indicative of guilt related to the crime for which their being interviewed.
If they weren't suspecting me at the time, I'd be terrified of now causing them to look at me cockeyed after invoking lawyer. I also dread making anybody mad at me, certainly not anybody in law enforcement - I want those guys on my side!