Ye, that's an obvious giveaway.
If he makes up his mind to use a recovery service then he should know that there's always a possibility of no recovery disregarding Recovery service lying.

Also, it's not like the service holders are going to know instantly that this is a bitcoin wallet private key unless they use the wallet or have 3rd party information gathering on the data they recover.
Or he can directly tell the service providers what's in it and they'll get some percent of it after a successful recovery.