Medicals expiry period ?

Medicals expiry period ?
I have heard that medicals expire within 1 year. My question is how this period is calculated ?

a ) 1 year from the date the medical notice is issued ? b ) 1 year from the date primary applicant finishes medicals ? c ) 1 year from the date the whole family finishes medicals including various referrals to specialists.

My family was examined by designated doctor in aug 2008 , but later on me and my wife were referred to specialists in different hospitals till nov. 2008 and we completed the last referral to a specialist in nov. 2008. We cleared the medicals and were asked to submit the passports by 30th may 2009. At this point very unfortunately my passport was misplaced/lost .I personally went to cic office and told them the facts ,they were very helpful and sympathetic and assured me not to worry. I was told if I find my passport by 9th of aug.2009 my medicals will be valid.If I am not able to find then me and my wife & kids will have to undergo fresh medicals again. Fortunately/unfortunately I could trace my passport and found it only on 12th aug. 2009.
This is the reason I am asking how come the medicals are valid only till 9th aug.2009 and not nov2009. end when all the reports were completed /sent to cic.I even got a letter towards oct 2008 end informing me that they have not yet finalized a decision about me and need more reports for my wife to come to a conclusion.Can some body who is knowledgeable tell me if they are right about the expiry dates or there is some chance to appeal through a lawyer, or I should go and talk to them or there is no point and I should undergo medicals again. I will appreciate to hear from you your opinion. Thanks in advance.