i see both sides. i think from a truly BUSINESS standpoint, what he did is normal and acceptable.
however, if you are in something as a hobby, common courtesy should be a must.
example, if i work at petsmart and someone comes in a says i want that ball python, and they say "ok" then you have to go out and get money or whatever, and they sell it to the next person, thats business, and that should be viewed as fine and dandy. however, if i have a snake to sell (as a hobbiest, which is what i am with reptiles), and i post it and someone says, i will take it, i always, always give them 48-72 hours buffer, just as a common courtesy and a just incase, to allow for financial situations to be in place, proper communications to happen and take place and final deals being agreed upon.
now, unless i missed something, if the add says, must sell now or sell to the best offer, or something along those lines, that is one thing. i didnt notice any of that being said here.
however, i dont believe this should have been tagged a bad guy thread, especially so quickly
ps, these are my personal thoughts, opinions and ways i conduct myself. i am not a business/money oriented guy, especially in ways with something i consider a pure hobby