Is it a legal transfer of ownership?

My friend and I registered an LLC about a year ago with each of us as 50% owners. About a month after it was registered he decided he didn't want to do it anymore so I bought him out for $500.00. Since the Business was Literally just a name of an LLC with no ets liabilities or equity of any kind I simply wrote up a transfer of ownership doent saying upon signing this I would be the full owner and he would not have any ownership stake. However I forgot to have him date the doent. Could this be a problem? I have a copy of the $500.00 check I gave to him in my online bank account records (which he signed and cashed) with the FOR part of the check saying "Full ownership stake in ******** LLC". Is this good enough for a transfer of ownership. Note: I am not going to a lawyer to transfer ownership as that would cost more money than simply dissolving the LLC and then restarting it again under my name only and I could never convince him to go to a lawyers office anyway as that would be inconvenient for him (in his opinion). Thanks