Did this with a SEPA transfer on bitquick once. The guy sent me 180 euro. I saw the transfer go through to my account. I released the bitcoins.
2 days later my bank calls me and says the person's account that sent me the money was hacked and that they needed to refund the 180 euro. Nothing I could do at that point.
Yeah, this is why they introduced real name and ID verification at Localbitcoin. Bitsquare doesn't appear to have such protections, or indeed a rep system, but appears to rely on the assumption that hackers won't be bothered for sums of one Bitcoin or less...