Please do not accuse anyone in public of cheating. Not fair and unprofessional... Any such matters will be dealt in private, since in 99% of the cases there is nothing wrong going on and absolutely no cheating.
* New airlines get heavy discounts of the slot fees, for you a set of 7 day slots today might be 1.6mil but for him it might be 0.6mil (depends on the times too, just an example). You had the same discounts when you started and the price goes up quickly.
* The amount of initial cash also goes up when the game progresses. So if your start-up cash was for example 20mil, he could have started with 22mil. (just examples)
* 2x planes to start, 2x planes on order, each having about 4-5 daily routes; that's 19 in total. Very normal if you fly short sectors.
* Probably no cash reserves left after spending all on planes & slots.. generally a bad idea. Time will tell.