The author of the book I read this in didn't seem to take the obvious next step and acknowledge that the consequences model is clearly The Correct Way to Make Decisions and basically by definition, if you're using the identity model and it's giving you a different result then the consequences model would, you're being led astray.

This statement is too strong. Your analysis of the consequences could be faulty (buggy wetware and such), while the identity model is presumably built on the trial, error and wisdom of many people smart enough to create that identity. I'd rather acknowledge the discrepancy (notice the confusion) and try to figure out where and why the results differ, without assuming that "personal consequentialism is right" and "group identity-based deontology is wrong".