Cooldgamer can definitely be trusted, I have only ever done a transaction on this website requiring trust once, that was when I sold BTC to cooldgamer for Paypal.
However, circumstances can and do change, we don't know what could be happening in somebody's personal life, this is why you should always retrieve some form on immediate contact information, for example, a phone number linked to his residential address.
This may or may not mean his account has been sold, but that's not the only possibility. Trustworthy members do go through financial hardships and have late payments. Just because he has been around for long doesn't mean he'll always be able to come up with the money.
Also, not sure if this is relevant or not, but his profile pic seems to be different from the last time I saw his profile.
Hey man, thanks for all this info, especially the info about the avatar possibly slightly changing. This very much puts my mind at ease two weeks after the loan was due and was repaid on time