I assume he thought any penalties where financial. Over inflated sponsorship, off book payments and thus accounting fraud on FFP would be relegation and is vastly more serious than Everton's issues.
They should have looked at FFP to confirm if the potential sanctions were worth it.
Anyone advising him at Due Diligence stage with half a brain would tell him :
1 There are very substantial risks of mis-statement of figures, high risk of offshore payment with tax and ffp consequences etc. There will be risks not uncovered in DD
2 Downside risks cannot be quantified = very deep pockets required to go ahead with many hundreds of millions if not a billion or two of money required on top of original investment to solve the problems.
3 FFP/Profit and Sustainability rules have teeth - ensure your business models include ffp effects.
Usually ffp penalties are NOT allowable for tax and therefore have a much bigger effect than you might initially think
Nobody can stop an idiot investing (as Musk has proved) , just make sure they understand the easy bit is putting money in. Sorting out the pig sty which is Chelsea finances will cost mega bucks and take years