> Could the EU put out an arrest warrant on themIANAL but I would expect EU antitrust law is a civil matter, not penal, so no, jail would be off the table. The EU has no police corps and no real "law" - it emanates resolutions that countries then turn into laws, and provides a location where treaties can be signed. Some of these laws and treaties define certain specific roles for certain EU authorities.
This is why the EU Commission will only ever emit "fines" and "sanction infractions", rather than prosecuting this or that person.
This said, the usual procedure is to perpetuate and escalate fines: they will fine you the first time, and if you keep misbehaving they will fine you pretty much every year, plus compounded interest of course. If you don't pay, they can ask specific countries to act and freeze or requisite your assets, or worse - depending on the laws of the specific country. Countries can (and occasionally do) choose to ignore these demands, but it would result in sanctions against the country, which are directly taken out of payments from the EU budget (for infrastructural work, education etc etc). This is, incidentally, why Ireland is forced to abide by the tax ruling on Apple: if they don't, EU funds will dry up until the whole sum is repaid.
In the worst-case scenario, the EU Commission could emit a directive banning all products from Qualcomm in the EU market, and let fines spiral into the trillions, but somehow I don't expect this will actually happen.