You cannot be issued a normal Visa or Extension beyond the expiry date of a passport. I think your friend got a new passport as the old one was nearly full so in this case he would get the full Visa or Extension and had the stamps transferred to the new passport. [DTV, LTR and other non-normal Visas can be issued beyond the expiry of a current passport]
The fact you didn't take the 30 day extension will possibly work in your favour as you did not max out your first stay then try to re-enter soon after to repeat. Have the 3 proofs just in case you are questioned :
- proof of accommodation for at least your first few nights (hotel booking or a letter of invite from a Thai)
- proof of onward travel (international travel ticket leaving Thailand within your initial entry stamp exit by date)
- proof of funds (20,000 Baht or equivalent in any major currency in CASH per individual, or 40,000 for a family)
From 3 months after the first extension was granted up to the end of the first extension (9 months) the original 800k cannot fall below 400k (conditions for the first extension) and you need 12 consecutive international deposits of at least 65k at the time of application to meet the requirements for the next extension.
You have to have 800k banked to get the first 12 month extension unless your Embassy still does the income affidavit. 65k monthly transfers can be used from year 2 onwards.