Well, here's a cheery thought. The IRS has three years from date of filing to audit your tax returns. As long as you are not understating any type of income - and I am taking vary broad view here - - and you are not, overall, defrauding the US Treasury.
Hey, go for whatever you think is right. Especially if you think your CPA is "gaming" you.
I would have a lively discussion with the syndicator's CPA. You realize, of course, that by law LLC's in every state, must allow you to view the tax returns.
"Many states require an LLC to maintain certain records and provide that members have a right to inspect these records. These records include the names, addresses, contributions, and shares of profits and losses of each member, the names and addresses of managers, and certain tax returns. LLCs can expand or reasonably restrict the members' right to inspect books and records in their operating agreements."
Make the Syndicator spend money on a written tax opinion by HIS accountant. Be a nuisance! Contact other investors, see what they feel about this. Also, demand to speak with the law firm representing the LLC/Syndicator. Threaten to file a complaint with the Bar Association for sloppy work, and with the State Society of CPA's against the Syndicator's CPA firm.
Basically, throw your frustration and doubt back at them, because they caused it by not being upfront with you.
Best case, they are tired of dealing with you, and buy out your interest at Fair Market Value.
In any event, in three years you are likely to be home free.