Looking for Andrew in Prison

This is a story that is from those wonderful carefree days when Andrew was here with me in Thailand. One day, we resolved that he would spend the morning painting graffiti and I would wander around, and we'd meet up at his spot at 11:30am. So I left him:
At 11:15 I showed up and saw this:
But no Andrew! What would cause my good friend to abandon a piece halfway through? I thought for sure he had been spotted by the police or at least run off by some locals. I waited until 11:31 but thought he had bolted and didn't want to return to the scene of the crime, returning instead to where we were staying, which is where we had agreed to meet in case we missed each other at the spot.

So I went back to where we were staying and he wasn't there, and I thought for sure he had been arrested. I saw his parents and Andrew's mom asked "Did you lose my son?" and I laughed nervously and replied "Nno!" I chatted with them for a bit, the whole time thinking furiously how this could really ruin the trip for everyone, and they left. I had a feeling that if I sat around and did nothing Andrew would show up eventually, but I also had a terrible vision of him not returning and me having to explain to his parents why I hadn't told them anything sooner or done anything all day when I knew he was missing. In my head, I literally repeated the words: "This is an adult situation. You are an adult. You will deal with this situation AS AN ADULT." I ran and grabbed a map of Bangkok, pinpointed the closest police station to where Andrew was painting, hopped in a tuk tuk and told the driver to take me there:

"Why do you want to go there?"
"I'm looking for my friend."
"Your friend a policeman?"
"No."
"...Oh."

We zipped off, and when I told the driver I thought my friend had been arrested for graffiti, he told me he was pretty sure they don't arrest people for that. Maybe, I thought, but who knows what Andrew was painting on. The wall he chose was mysteriously bare of graffiti in a part of town that was pretty well covered, so I thought it might have been on the backend of an important landmark or something.

We arrived at the police station and the tuk tuk driver acted as interpreter. The police didn't look like they had much going on, they were very unhurried and weren't at all dismissive of me, in fact they seemed to enjoy the conversation. The police told me that they do not in fact arrest people for graffiti, but continued wanting to talk anyway about the wheres and the whats and things:

"Like this?" [pointing at a small tag nearby]
"No, more like that." [pointing at a larger piece across the street]
[Policeman nods his head appreciatively] "No arrest."

They gave me a Thai donut and told me if he hadn't shown up after 24 hours to come back. I was pretty nervous still, but when I got back to where we were staying THERE WAS ANDREW! I kicked a shoe at him, and was both a little angry and happy to see him.

So what happened?

Turns out Andrew went to go get some water at 11:14 and returned at 11:33. He waited around for me until 12:20, thought I got lost but that I'd sort it out, then left a "BRB" message on the wall while he went to get more paint. When he returned and I still wasn't there he got more worried, updated his note and went back to the hotel:
He took a shower, and as he was getting out I walked in and kicked a shoe at him. He got a little angry but was happy to see me.

The finished piece, with a couple of additional throwups he did while waiting for me: