what should i have done?

[mostsmooth]

im leaving home depot. im parked in fron of a mini van that wasnt there when i got there. ive been inside for about 25 minutes. the mini van is running. at least one window is slightly cracked open. i assumed the air conditioning was on, but then why would the window be cracked open? the driver side door appears to be unlocked when compared to the passenger side door. a dog sits on the passenger side seat. he doesnt look uncomfortable. when he sees me he barks occasionally, but the bark wasnt an 'im gonna attack you' bark, it seems more like a 'this is suck' bark.
what should i have done?