Unless the defense attorney bought his degree out of a bubblegum machine, I can assure you the chain of evidence problems will be presented. It's possible that this will give a juror reasonable doubt.
http://criminal.findlaw.com/criminal-procedure/how-to-suppress-evidence.html
Chain of Custody Errors: The “chain of custody” refers to the documentation and proper care of evidence, from its seizure by police to its presentation at trial. If the chain of custody is broken, the evidence may lack credibility and could be deemed inadmissible.
MOO
Where was the chain of custody broken in this case? Did the tow truck driver turn his keys over to someone? When and where and how did he break the chain of custody? The car was on his truck and he was in control of it, afaik. That's all the chain of custody means. It was never out of his control.
A defense attorney who thinks there is a believable chain of custody issue that will persuade a jury not to convict in this case really shouldn't be practicing criminal law, imo. Perhaps a specialty in permits and inspections would be a better fit.
JMO