Hi, I'm newer to YT and am not currently an owner (searching now) but I am a Sales professional I guess you'd say...I totally agree w/ what you did, 1st come 1st served...as a potential buyer, until I say "I want him, I will contact you tomorrow about payment" then I take that chance.
I manage an apt complex in a college town...spaces are limited and demand is high. I was always told to be a high pressure saleswoman, but I just don't have it in me to feed someone full of fluff, whether or not its truth. But, if I only have 1 apt and someone is looking at it and says they will get back w/ me, sometimes they do, more often not. I just simply tell them that I cannot take the unit off the market w/o a deposit. I will also state that I can work w/ them on postdating a check for a couple days or something. It is always best policy to be honest, of course, and until someone has made a monetary commitment they haven't made up their minds.
Sorry that you had to deal w/ this, but I beleive that you made the right decision and that precious baby will be happy in his home for years to come!