mfly, you'll no doubt get a flood of posts telling you "Pinnacle is as solid as a rock", not to worry.
So don't.
Pinnacle is a good out for many, but for reasons that probably have little to do with "safety only" as a consideration.
Obviously your "safest out" would be a guy who occured no or little risk in taking your bet. A guy who owned the local bar (and sheriff) and only took $100 max bets on sides at -110 would be as SAFE as you could get, you KNOW he's going to pay you.
As books get bigger and take more action, the risk increases. IMO Pinnacle's "business model" of low juice coupled with taking sharp action occurs more risk than your local bar owner taking $100 bets at -110 would occur, or a book taking sides at $500 max -110 would occur, and the posts here probably reflect that feeling too.