You're allowed to disagree - that's the joy of this thread. However, unless you can statistically prove that what you're saying is true, i will respectfully disagree with you. Forgive me if this sounds condescending - it's not meant that way - but you are coming at this from a perception / experience point of view. I totally get that - i'd have said the same before i came to "this side" of the games. However, i'm coming at it from the point of view of knowledge. I will caveat that by saying i can not be 100% sure that some providers do not do some underhand things BUT I would stake my life on the fact that ALL the major providers do not do this. It's more than their licence is worth - their licence is their business. Without it they have no business... it's just not worth doing anything like that.
Also, there's just no point. For example - you say the casino has just made $100 off you right? So they can afford to loosen the slot up - right? Wrong - the game has an RTP. When you lose the $100, someone else is winning $97 (assuming a 97% RTP). I know that's simplistic, but it's fact. If they then "loosen" it up for you, and the other player withdraws his $97 and then you withdraw your money that this new "loose" slot has given you, the casino lose.
Anyway -
in my experience i don't know of any slots provider that does this, and as the casinos have no control over the slot content (unless it was developed in house - then there is a chance they could) i'm afraid your experience is just an experience, and unlikely to be fact.
Sorry for disagreeing - but hey, that's what this thread is for. I don't expect everyone to believe me, but some peoples minds are not for changing, and i'm sure there will be some who just think "more bullshit from someone in the industry - lying bastards" - and that's fine... i was there once!