IG As a BAD Platform

I do not use a Spread betting platform...so let us get this out of the way to start with...So I have NO affiliation with with these platforms at all...So I speak from the heart and what 34 years trading has taught me....On NUMEROUS occasions it has been bought to my attention just how bad IG is....So I decided to trial this platform, along with others, so I could compare...This was after the SNB ( Swiss National Bank ) debacle of 2015.....Traders I knew were wiped out by IG...and pursued for outstanding amounts running into 100's of 1000's individually....One very close friend of mine was Short USD/CHF...Long EURO/CHF....and told when he was wiped out that the USD/CHF was voided after extreme market conditions....Well...why wasnt the EUR/CHF voided as well...That if anything was under " extreme " market conditions....They had no answer...and have persued him for over a year to the point he has given up trading....So lets take last night when "GBP/USD " was in freefall....So you have 2 platforms....I will name them....CMC and IG.....both had EXACTLY the same order and EXACTLY the same stop.....CMC filled the stop on the Euro/Stg AT THE STOP PRICE.thus limiting the exposure...IG however filled the stop 20 MINS LATER at a loss of EIGHT times the difference....Now how on earth can that be.....The market was up at stupid levels less than 5 MINUTES...So how does a platform ACTUALLY fill an stop order 20 MINS later at a price which was not even trading !!!!!!!!!!!!...So to give IG the benefit of the doubt we rang them.....NOw bear in mind...the order was run on CMC and IG......