Just a personal view but I think that anyone who wears a military jacket that they are obviously not entitled to is just making a complete arse of themselves and are being a tad disrespectful to those who wear the uniform legally, (unless it is a private party etc).
Two points, I believe it is an offence to wear military medals in public that you are not entitled to.
It is my understanding that if one wears medals on behalf of another at a remembrance parade or suchlike then they should be worn on the right side of the chest.