Evans was allowed to leave for Leicester City this summer for a snippet of his market value thanks to a clause written into his contract when he was signed from Manchester United for £6m back in 2015.
Last summer Albion rejected bids of £18m and £21m from Manchester City and Leicester respectively and in January they turned down £12m from Arsenal.
But Garlick, who helped draw up the contract in his role as director of football administration, says the clause made sense at the time because it was crucial to getting the Northern Irishman to come to The Hawthorns.
When he was asked if he regretted the clause he said: “In hindsight yes, but let’s face it, we have had the opportunity to sell him and made a decision not to sell for more money than what he went for.
“(It’s about) the compromises you make and the price of signing players and what you need to throw into a negotiation to attract players.
“When you sign ex-Manchester United players who have got a view they can move on to the next stage they’re going to want some sort of protection in relation to where they can and can’t move.
“Particularly on a relegation, that buyout was only relevant to a relegation, because they don’t see themselves ever having to play in the Championship.
“We paid £6m for Jonny, Man United didn’t have a sell-on – that tells you where they thought he was.
“Obviously he’s done very well, probably better than us and Man United expected. At the time, there was a doubt about him.
“The market has moved as well. The danger of putting those clauses in there is that when the market moves – as it did – they end up looking a bit of out of kilter. He’s spent three seasons with us, he’s done fantastically well and the club have done fantastically well, apart from last season.
“So if you look at it, that deal cost us £2.5m over three years, plus his wages obviously.
“You can look back and say ‘yes, it would have been great to have had a bigger clause’, but he wouldn’t have signed. He’s been at Man United for all his career and he’s got aspirations about where he wants to play.
“The club has to be prepared to be used as a bit of a stepping stone.
“If players come and do well for two or three years ideally, and they move on we should say ‘fantastic, you’ve been great for us and we all move on’.
“Sometimes everyone gets a little bit wanting to handcuff their players.
“We’re not the only club that would wants to keep hold of players. Why would you not want to keep hold of your best players?
“You could look back and say ‘do you regret the Jonny Evans one as much as I regret not signing (Romelu) Lukaku’ and then the market went nuts and he went for over £60m to Man United. But whose to say his pathway would have worked out as it has?
“The fact is, we’re in a fortunate position where we have got a lot of good players still in that squad that are assets to this club and we’re not in a financial situation where we need £20m to fill a black hole and Evans would have solved it.
“That Evans deal was done when Jeremy (Peace) and Mark (Jenkins) were here. It wasn’t done by people who were inexperienced in the market.
“We had chances to sell him, but we decided to keep him to give us the best opportunity to stay up. It’s a gamble that hasn’t worked.”