Is there a difference in my options if the seller lied on purpose versus just got the numbers wrong?

Yes, and it can matter significantly. An honest but inaccurate representation — a negligent or innocent misrepresentation — is typically addressed through the ordinary indemnity mechanics in the purchase agreement, subject to whatever survival period, cap, and basket the parties negotiated for that kind of claim at the time of the deal. A representation the seller actually knew was false when made is treated far more seriously.

Courts are generally much less willing to let a negotiated cap, basket, or even a short survival period protect a seller who deliberately lied, and fraud can open up broader remedies than what an ordinary contractual indemnity claim allows on its own. Whether conduct crosses from careless to deliberate is often the central, hard-fought factual question in disputes like this, since it changes both what's recoverable and what defences the seller can rely on. If you believe the seller knew the numbers were wrong, that distinction is worth raising with your lawyer specifically and early, rather than treating the claim as an ordinary indemnity dispute by default.